IP Commands

access-class

To restrict incoming and outgoing connections between a particular VTY and the addresses in an access list, use the access-class command. To remove access restrictions, use the no form of this command.

access-class access-list-name/number { in | out }

no access-class access-list-name { in | out }

Syntax Description

access-list-name/number

You can either enter a name of the access-list or a number.

Name of the IPv4 ACL class. The name can be a maximum of 64 alphanumeric characters. The name cannot contain a space or quotation mark.

Number of an IP access list. This is a decimal number from 1 to 199 or from 1300 to 2699 .

in

Restricts incoming connections between a particular Cisco device and the addresses in the access list.

out

Restricts outgoing connections between a particular Cisco device and the addresses in the access list.

Command Default

None

Command Modes

Line configuration mode (config-line)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE access-class command.

This example shows how to configure an access class on a VTY line:

Device (config)# line vty 0 5    
Device(config-line)# access-class TEST in

address prefix

To specify an address prefix for address assignment, use the address prefix command in interface configuration mode. To remove the address prefix, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE address prefix command.

The following example shows how to configure a pool called engineering with an IPv6 address prefix:

Device(config)# ipv6 dhcp pool engineering
Device(config-dhcpv6)# address prefix 2001:1000::0/64 lifetime infinite

arp timeout

To configure how long a dynamically learned IP address and its corresponding Media Control Access (MAC) address remain in the Address Resolution Protocol (ARP) cache, use the arp timeout command in interface configuration mode. To restore the default value, use the no form of this command.

arp timeout seconds

no arp timeout

Syntax Description

seconds

Time (in seconds) that an entry remains in the ARP cache.

The general recommended value for ARP timeout is the configured default value, which is 4 hours. If the network has frequent changes to cache entries, change the default to a shorter time period. As you reduce the ARP timeout, your network traffic increases. A low ARP timeout value might lead to network outage, and a value less than an hour (or 3600 seconds) will generate significantly increased traffic across the network.

Caution

 
We recommend that you set an ARP timeout value greater than 60 seconds.

Command Default

14400 seconds (4 hours)

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates

Usage Guidelines

For the usage guidelines, see arp timeout. 

Device(config)# interface GigabitEthernet 1
Device(config-if)# arp timeout 7200

cdp enable

To enable Cisco Discovery Protocol on an interface, use the cdp enable command in interface configuration mode. To disable Cisco Discovery Protocol on an interface, use the no form of this command.

cdp enable

no cdp enable

Syntax Description

This command has no arguments or keywords.

Command Default

This command is enabled at the global configuration level and is supported on all interfaces.

Command Modes


Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see cdp enable. 

Device(config)# interface GigabitEthernet 1
Device(config-if)# cdp enable

cdp run

To enable Cisco Discovery Protocol, use the cdp run command in global configuration mode. To disable Cisco Discovery Protocol, use the no form of this command.

cdp run

no cdp run

Syntax Description

This command has no arguments or keywords.

Command Default

This command is enabled on all the platforms.

Command Modes


Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE cdp run command.

In the following example, Cisco Discovery Protocol is enabled globally.


Device(config)# cdp run

default-router

To specify the default router list for a Dynamic Host Configuration Protocol (DHCP) client, use the default-router command in DHCP pool configuration mode. To remove the default router list, use the no form of this command.

default-router address [address2 . . . address8]

no default-router

Syntax Description

address

Specifies the IP address of a router. One IP address is required, although you can specify up to eight addresses in one command line.

address2...address8

(Optional) Specifies up to eight addresses in the command line.

Command Default

No default behavior or values.

Command Modes

DHCP pool configuration (dhcp-config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE default-router command.

The following example specifies 10.1.19.15 as the IP address of the default router:

Device(config)# ip dhcp pool POOL1
Device(dhcp-config)# default-router 10.1.19.15

dns-server

To specify the Domain Name System (DNS) IP servers available to a Dynamic Host Configuration Protocol (DHCP) client, use the dns-server command in DHCP pool configuration mode. To remove the DNS server list, use the no form of this command.

dns-server address [address2 . . . address8]

no dns-server

Syntax Description

address

The IP address of a DNS server. One IP address is required, although you can specify up to eight addresses in one command line.

address2...address8

(Optional) Specifies up to eight addresses in the command line. The server addresses should be specified in the order of preference.

Command Default

If DNS IP servers are not configured for a DHCP client, the client cannot correlate host names to IP addresses.

Command Modes

DHCP pool configuration (dhcp-config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

Servers are listed in order of preference (address1 is the most preferred server, address2 is the next most preferred server, and so on).

The following example specifies 10.12.1.99 as the IP address of the domain name server of the client: 


Device(config)# ip dhcp pool POOL1
Device(dhcp-config)# dns-server 10.12.1.99

domain-name

To specify the default domain for a Domain Name System (DNS) view to use to complete unqualified hostnames (names without a dotted-decimal domain name), use the domain-name command in DHCP pool configuration mode. To remove the specification of the default domain name for a DNS view, use the no form of this command.

domain-name domain-name

no domain-name

Syntax Description

domain-name

Default domain name used to complete unqualified hostnames.

Note

 

Do not include the initial period that separates an unqualified name from the domain name.

Command Default

No default domain name is defined for the DNS view.

Command Modes

DHCP pool configuration (dhcp-config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE domain name command.

The following example shows how to define dns1 as the default DNS view for the DHCP pool named POOL1.


Device(config)# ip dhcp pool POOL1
Device(dhcp-config)# domain-name dns1

ip address

To set a primary or secondary IP address for an interface, use the ip address command in interface or sub-interface configuration mode. To remove an IP address or disable IP processing, use the no form of this command.

ip address ip-address [mask]

no ip address [ip-address] [mask]

Syntax Description

ip-address

IP address.

mask

(Optional) Mask for the associated IP subnet.

Command Default

No IP address is defined for the interface.

Command Modes

Interface configuration (config-if)

Sub-interface configuration (config-subif)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see the Cisco IOS XE ip address command. 

Device(config)# interface ATM 0/3/0.1 point-to-point                                                                                            
Device(config-if)# ip address 192.10.6.5
Device(config)# interface ATM 0/3/0.1                                                                                                
Device(config-subif)# ip address 10.0.0.0 255.255.255.252
Device(config)# interface Serial 0/1/0.2                                                                                            
Device(config-if)# ip address 10.1.1.1 255.255.255.0
Device(config)# interface Serial 0/0/1:5                                                                                            
Device(config-if)# ip address 10.1.1.1 255.255.255.0
Device(config)# interface MFR1                                                                                            
Device(config-if)# ip address 10.4.4.4 255.255.255.0

ip address dhcp

To acquire an IP address on an interface from the DHCP, use the ip address dhcp command in interface configuration mode. To remove any address that was acquired, use the no form of this command.

ip address dhcp [ client-id interface-type number ]

no ip address dhcp [ client-id interface-type number ]

Syntax Description

client-id

(Optional) Specifies the client identifier. By default, the client identifier is an ASCII value. The client-id interface-type number option sets the client identifier to the hexadecimal MAC address of the named interface.

interface-type

(Optional) Interface type. For more information, use the question mark (?) online help function.

number

(Optional) Interface or subinterface number. For more information about the numbering syntax for your networking device, use the question mark (?) online help function.

Command Default

The client identifier is an ASCII value.

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see ip address dhcp. 

Device(config)# interface GigabitEthernet 1                                                                                             
Device(config-if)# ip address dhcp client-id GigabitEthernet 1

ip arp proxy disable

To globally disable proxy Address Resolution Protocol (ARP), use the ip arp proxy disable command in global configuration mode. To reenable proxy ARP, use the no form of this command.

ip arp proxy disable

no ip arp proxy disable

Syntax Description

This command has no arguments or keywords.

Command Default

Proxy ARP is enabled.

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

The ip arp proxy disable command overrides any proxy ARP interface configuration. The default ip arp proxy command returns proxy ARP to the default behavior, which is enabled.

The following example disables proxy ARP: 


Device(config)# ip arp proxy disable

The following example enables proxy ARP: 


Device(config)# no ip arp proxy disable

ip bootp server

To enable the Bootstrap Protocol (BOOTP) service on your routing device, use the ip bootp server command in global configuration mode. To disable BOOTP services, use the no form of the command.

ip bootp server

no ip bootp server

Syntax Description

This command has no arguments or keywords.

Command Default

Enabled

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip bootp server command.

In the following example, the BOOTP service is enabled and disabled on the router: 


Device(config)# ip bootp server
  
Device(config)# no ip bootp server

ip cef load-sharing algorithm

To select a Cisco Express Forwarding load-balancing algorithm for IPv4, use the ip cef load-sharing algorithm command in global configuration mode. To return to the default universal load-balancing algorithm, use the no form of this command.

ip cef load-sharing algorithm { universal [id ] | include-ports [ source [id ] | destination [id ] ] | src-only [id ] }

no ip cef load-sharing algorithm

universal [id]

Sets the load-balancing algorithm to the universal algorithm that uses a source and destination IP. (This is set as default).

id

(Optional) Fixed identifier.

include-ports {source [id] | destination[id]

Sets the load-balancing algorithm to include source port and destination port.

src-only [id]

Sets the load-balancing algorithm to include source-only port.

Command Default

The universal load-balancing algorithm is selected. If you do not configure the fixed identifier for a load-balancing algorithm, the router automatically generates a unique ID.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.6.1a

This command was introduced.

Cisco IOS XE Catalyst SD-WAN Release 17.8.1a

This command was modified. The src-only algorithm is added.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip cef load-sharing algorithm command.

You can enable ECMP keying to send the configurations for both IPv4 and IPv6.

The following example shows how to enable the CEF load-balancing algorithm for universal:


Device# config-transaction
Device(config)# ip cef load-sharing algorithm universal

The following example shows how to enable the IP CEF load-sharing algorithm to include source and destination ports algorithm:


Device# config-transaction
Device(config)# ip cef load-sharing algorithm include-ports source destination
Device(config)# commit

The following example shows how to enable CEF load-sharing algorithm to src-only port algorithm:


Device# config-transaction
Device(config)# ip cef load-sharing algorithm src-only [id]
Device(config)# commit

ip-clear-dont-fragment

ip clear-dont-fragment —Clear the Don't Fragment (DF) bit in the IPv4 packet header for packets being transmitted out the interface. When the DF bit is cleared, packets larger than that interface's MTU are fragmented before being sent.


Note

ip clear-dont-fragment clears the DF bit when there is fragmentation needed and the DF bit is set. For packets not requiring fragmentation, the DF bit is not affected.

The option to clear the Dont Fragment bit is available for Cisco SD-WAN tunnels interfaces only.

By default, the clearing of the DF bit is disabled.

vManage Feature Template

Configuration ► Templates ► Cellular Interface

Configuration ► Templates ► VPN Ethernet Interface

Configuration ► Templates ► VPN Interface DSL IPoE

Configuration ► Templates ► VPN Interface DSL PPPoA

Configuration ► Templates ► VPN Interface DSL PPPoE

Configuration ► Templates ► VPN Interface Multilink

Configuration ► Templates ► VPN Interface T1/E1

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.5.1a Qualified for use in Cisco vManage CLI templates

Usage Guidelines

For more information about this command, see the Cisco IOS XE clear-dont-fragment

Example

This example shows how to clear the DF bit in IPv4 packets being sent out an interface:


Device# config-transaction
Device(config)#interface Tunnel 1
Device(config-if)#ip unnumbered GigabitEthernet1
Device(config-if)#ip clear-dont-fragment
Device(config-if)#

ip dhcp client vendor-class

By default the DHCP client carries PID (Product ID) of the device in option-124. This default behaviour can be overridden by configuring below CLI:

ip dhcp client vendor-class [ mac-address | ascii | | hex | | disable ]

Syntax Description

mac-address

The mac address of the device.

ascii

The user defined string in ascii format.

hex

The user defined string in hexadecimal format.

disable

Disables sending option-124 to DHCP messages.

Command Default

By default option-124 carries PID of the device.

Command Modes


Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.10.1a

This command was introduced.

Usage Guidelines

By default the DHCP client carries PID of the device in option-124. This default behaviour can be overridden by configuring the ip dhcp client vendor-class command.

The following example shows the configuration to override the decive PID with MAC address:


interface GigabitEthernet 0/0/0
    ip address dhcp
    ip dhcp client vendor-class mac-address
    !

The DHCP vendor-class option, overrides the Device PID with MAC Address.

The following example shows the configuration to override the device PID with user defined string in hex or in ascii format:


interface GigabitEthernet 0/0/0
    ip address dhcp
    ip dhcp client vendor-class hex aabbcc
    !


interface GigabitEthernet 0/0/0
    ip address dhcp
    ip dhcp client vendor-class ascii cisco
    !

The following example shows the configuration to disable option-124 in DHCP messages:


interface GigabitEthernet 0/0/0
    ip address dhcp
    ip dhcp client vendor-class disable
    !

ip dhcp use

To control what information the Dynamic Host Configuration Protocol (DHCP) server accepts or rejects during address allocation, use the ip dhcp use command in global configuration mode.

To disable the use of Dynamic Host Configuration Protocol (DHCP) parameters during address allocation, use the no form of this command.

ip dhcp use { class | vrf remote }

no ip dhcp use class

Syntax Description

class

Specifies that the DHCP server use DHCP classes during address allocation.

vrf

Specifies whether the DHCP server ignores or uses the receiving VPN routing and forwarding (VRF) interface during address allocation.

Command Default

The DHCP server allocates addresses by default.

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

When the Cisco IOS DHCP server code is allocating addresses, you can use the ip dhcp use command to either enable or disable the use of VRF configured on the interface, or to configure DHCP classes. If you use the no ip dhcp use class command, the DHCP class configuration is not deleted.

For usage guidelines, see Cisco IOS XE ip dhcp use command.

The following example shows how to configure the DHCP server to use the relay agent information option during address allocation:

Device(config)# ip dhcp use class

The following example shows how to configure the DHCP server to enable the use of the VRF configured on the interface during address allocation: 

Device(config)# ip dhcp use vrf remote

The following example shows how to configure the DHCP server to disable the use of class during address allocation:


Device(config)# no ip dhcp use class

ip dhcp smart-relay

To allow the Cisco Dynamic Host Configuration Protocol (DHCP) relay agent to switch the gateway address (giaddr field of a DHCP packet) to secondary addresses when there is no DHCPOFFER message from a DHCP server, use the ip dhcp smart-relay command in global configuration mode. To disable this smart-relay functionality and restore the default behavior, use the no form of this command.

ip dhcp smart-relay

no ip dhcp smart-relay

Syntax Description

This command has no arguments or keywords.

Command Default

Command is disabled

Command Modes

Global configuration (config)

Command History

Release Modification
Cisco IOS XE Catalyst SD-WAN Release 17.13.1a

This command was introduced.

Usage Guidelines

The DHCP relay agent attempts to forward the primary address as the gateway address. After three attempts and no response, the relay agent automatically switches to secondary addresses.

Example

The following example enables the DHCP relay agent to automatically switch to secondary address pools:

Device(config)# service dhcp
Device(config)# interface GigabitEthernet0/0
Device(config)# ip address 172.16.0.1 255.255.0.0
Device(config)# secondary ip address 192.168.255.254 255.255.0.0
Device(config)# ip helper-address 10.0.0.1
Device(config)# ip dhcp smart-relay
Device(config)# end
!

ip dhcp use hardware-address client-id

To set the hardware-address as a client-id on all dhcp requests, use the ip dhcp use hardware-address client-id command in global configuration mode. To remove the hardware-address as the client-id, use the no form of this command.

ip dhcp use hardware-address client-id

no ip dhcp use hardware-address client-id

Syntax Description

This command has no keywords or arguments.

Command Default

None

Command Modes

Global configuration (config)

Command History

Release Modification
Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command is qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

Subscriber-id, vrf-id, hardware-address can be used as client-id in DHCP requests. Use this ip dhcp use hardware-address client-id command to set the hardware-address as a client-id on all DHCP requests.

Examples

The following example shows how to set the client-id of dhcp requests to use the hardware-address.

Device(config)# ip dhcp use hardware-address client-id
Table 1. Related Commands

Commands

Description
ip dhcp use class

DHCP server to use the relay agent information option during address allocation.
ip dhcp use subscriber-id

DHCP server to use the subscriber-id information option during address allocation.
ip dhcp use vrf

DHCP server to use the VRF information option during address allocation.

ip directed-broadcast

To enable the translation of a directed broadcast to physical broadcasts, use the ip directed-broadcast interface configuration command. To disable this function, use the no form of this command.

ip directed-broadcast

no ip directed-broadcast

Syntax Description

This command has no arguments or keywords.

Command Default

Disabled; all IP directed broadcasts are dropped.

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Release Amsterdam 17.2.1v

Qualified for use in Cisco vManage CLI templates

Usage Guidelines

For the usage guidelines, see ip directed-broadcast. 

csr8k(config)# interface GigabitEthernet 1.101
csr8k(config-if)# ip address 192.168.66.1
csr8k(config-if)# ip directed-broadcast

ip dns server

To enable the Domain Name System (DNS) server on a router, use the ip dns server command in global configuration mode. To disable the DNS server, use the no form of the command.

ip dns server

no ip dns server

Syntax Description

This command has no arguments or keywords.

Command Default

The DNS server is disabled.

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1r

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

Use this command to enable the DNS server as needed.

In the following example, the DNS server is enabled: 


Device(config)# ip dns server

ip domain lookup

To enable the Domain Name Server (DNS) lookup feature, use the ip domain-lookup command. Use the no form of this command to disable this feature.

ip domain lookup

no ip domain lookup

Syntax Description

This command has no arguments or keywords.

Command Default

None

Command Modes


Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1r

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip domain lookup command.

This example shows how to disable the DNS server lookup feature:

Device(config)# no ip domain-lookup

ip finger

To configure a system to accept Finger protocol requests (defined in RFC 742), use the ip finger command in global configuration mode. To disable this service, use the no form of this command.

ip finger

no ip finger

Command Default

Disabled

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

The following example disables the Finger protocol: 


Device(config)# no ip finger

ip helper-address

To enable forwarding of User Datagram Protocol (UDP) broadcasts, including Bootstrap Protocol (BOOTP), received on an interface, use the ip helper-address command in interface configuration mode. To disable forwarding of broadcast packets to specific addresses, use theno form of this command.

ip helper-address address

no ip helper-address address

Syntax Description

address

Destination broadcast or host address to be used when forwarding UDP broadcasts. There can be more than one helper address per interface.

Command Default

UDP broadcasts are not forwarded.

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see ip helper-address.

The following example shows how to define an address that acts as a helper address: 

Device(config)# interface GigabitEthernet 1.101
Device(config-if)# ip nbar protocol-discovery
Device(config-if)# ip helper-address 10.8.4.5

ip host

To define static hostname-to-address mappings in the Domain Name System (DNS) hostname cache for a DNS view, use the ip host command in global configuration mode. If the hostname cache does not exist yet, it is automatically created. To remove a hostname-to-address mapping, use the no form of this command.

ip host [ vrf vrf-name ] [ ip-address1 . . . [ ip-addressn ] ]

no ip host [ vrf vrf-name ] [ ip-address1 . . . [ ip-addressn ] ]

Syntax Description

vrf vrf-name

(Optional) The vrf-name argument specifies the name of the Virtual Private Network (VRF) routing and forwarding (VRF) instance whose hostname cache is to store the mappings. Default is the global VRF (that is, the VRF whose name is a NULL string).

hostname

Name of the host. The first character can be either a letter or a number. If you use a number, the types of operations you can perform (such as ping) are limited.

ip-address1 . . . ip-addressn

Associated host IP address. You can specify an IPv4 or IPv6 address for the host IP address and additional IP addresses.

(Optional) Additional associated IP addresses, delimited by a single space.

Note

 

The ellipses in the syntax description are used to indicate a range of values. Do not use ellipses when entering host IP addresses.

Command Default

No static hostname-to-address mapping is added to the DNS hostname cache.

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1r

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip host command.

The following example shows how to add a mapping entry to the hostname vbond.ubi.in and IPv4 address 10.0.0.0 with list of IP addresses associated with a hostname. 

Device(config)# ip host vbond.ubi.in ip-list 10.0.0.0

The following example shows how to add two mapping entries to the hostname that is associated with the VRF 101 and then remove one of those entries from that hostname cache: 


Device(config)# ip host vrf 101 test-1 192.0.2.141 192.0.2.241
 
Device(config)# no ip host vrf 101 test-1 192.0.2.141

ip host ip-address

To define static hostname-to-address mappings in the Domain Name System (DNS) hostname cache for a DNS view, use the ip host command in global configuration mode. If the hostname cache does not exist yet, it is automatically created. To remove a hostname-to-address mapping, use the no form of this command.

ip host [ ip-address1 . . . [ ip-addressn ] ]

no ip host [ ip-address1 . . . [ ip-addressn ] ]

Syntax Description

ip-address1 . . . ip-addressn

IP address of Cisco Catalyst SD-WAN Validator. You can specify an IPv4 or IPv6 address for the host IP address and additional IP addresses.

(Optional) Additional associated IP addresses, delimited by a single space. You can configure a maximum of 24 IP addresses.

Note

 

The ellipses in the syntax description are used to indicate a range of values. Do not use ellipses when entering host IP addresses.

Command Default

No static hostname-to-address mapping is added to the DNS hostname cache.

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1r

Qualified for use in Cisco vManage CLI templates.

The following example shows how to add two Cisco Catalyst SD-WAN Validator IP addresses as IP hosts, and how to remove one of them. 


Device(config)# ip host 192.0.2.141 192.0.2.241
 
Device(config)# no ip host 192.0.2.141

ip http authentication

To specify a particular authentication method for HTTP server users, use the ip http authentication command in global configuration mode. To disable a configured authentication method, use the no form of this command.

ip http authentication local

no ip http authentication [local]

Syntax Description

local

Indicates that the login user name, password and privilege level access combination specified in the local system configuration (by the username global configuration command) should be used for authentication and authorization.

Command Default

The “enable” password is required when users (clients) connect to the HTTP server. Three command privilege levels exist on the router.

Command Modes


Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip http authentication command.

The following example shows how to specify that the login user name, password and privilege level access combination specified in the local system configuration should be used for authentication and authorization. 


Device(config)# ip http authentication local

ip http client source-interface

To enable HTTP client on your IP or IPv6 system, use the ip http client command in global configuration mode. To disable the HTTP client, use the no form of this command.

Supported Parameters

type

Name of the source interface.
number

Number of the source interface.

Command History

Release Modification
Cisco IOS XE Catalyst SD-WAN Release 17.5.1a

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For more information about this command, see the Cisco IOS XE ip http client source-interface command.

Example

Device(config)# ip http client source-interface GigabitEthernet0/0/2

ip http secure-server

To enable a secure HTTP (HTTPS) server, use the ip http secure-server command in global configuration mode. To disable an HTTPS server, use the no form of this command.

ip http secure-server

no ip http secure-server

Syntax Description

This command has no arguments or keywords.

Command Default

The HTTPS server is disabled.

Command Modes


Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip http secure-server command.

In the following example the HTTPS server is disabled:


Device(config)# no ip http secure-server

ip http server

To enable the HTTP server on your IP or IPv6 system, including the Cisco web browser user interface, use the ip http server command in global configuration mode. To disable the HTTP server, use the no form of this command.

ip http server

no ip http server

Syntax Description

This command has no arguments or keywords.

Command Default

The HTTP server is disabled by default.

Command Modes


Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XEip http server command.

The following example shows how to disable the HTTP server:


Device(config)#no ip http server

ip http tls-version

To configure TLS version for HTTPS Server and HTTPS client sessions, use the ip http tls-version command in global configuration mode. To remove the configuration, use the no form of this command.

ip http tls-version tls-version

no ip http tls-version tls-version

Syntax Description

tls-version

Specifies TLS versions—TLSv1.0, TLSv1.1, TLSv1.2, and TLSv1.3.

Command Default

None

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.10.1a

This command was introduced.

Usage Guidelines

The ip http tls-version command allows you to set a particular version used for HTTP secure-server sessions. The underlying SSL infrastructure supports the option of specifying either all or only one TLS version. Hence the HTTPS provides the option to specify the individual version.

By default, three TLS versions used for HTTPS sessions are supported—TLSv1.2 and TLSv1.3. To enable a particular version use this command.

The following shows how to configure TLS version 1.0 for the HTTPS session:

Device(config)# ip http tls-version TLSv1.0

ip icmp rate-limit unreachable

To limit the rate at which Internet Control Message Protocol (ICMP) unreachable messages are generated for a destination, use the ip icmp rate-limit unreachable command in global configuration mode.

To use the default, use the no form of this command.

ip icmp rate-limit unreachable ms

no ip icmp rate-limit unreachable

Syntax Description

ms

The optional ms argument is a time limit in milliseconds (ms) in which one unreachable message is generated.

The valid range is from 1 ms to 4294967295 ms.

Note

 

Counting begins as soon as this command is configured.

Command Default

The default value is one ICMP destination unreachable message per 500 ms.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.3.1a

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip icmp rate-limit unreachable command.

The following example sets the rate of the ICMP destination unreachable message to one message every 10 ms: 


Device(config)# ip icmp rate-limit unreachable 10

The following example turns off the previously configured rate limit: 


Device(config)# no ip icmp rate-limit unreachable

ip icmp redirect

To control the type of Internet Control Message Protocol (ICMP) redirect message that is sent, use the ip icmp redirect command in global configuration mode. To set the value back to the default, use the no form of this command.

ip icmp redirect { host | subnet }

no ip icmp redirect

Syntax Description

host

Sends ICMP host redirects.

subnet

Sends ICMP subnet redirects.

Command Default

The router will send ICMP subnet redirect messages.

Because the ip icmp redirect subnet command is the default, the command will not be displayed in the configuration.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.3.1aexit

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip icmp redirect command.

The following example enables the router to send out ICMP host redirects: 


Device(config)# ip icmp redirect host

The following example sets the value back to the default, which is subnet redirects: 


Device(config)# ip icmp redirect subnet

ip igmp ssm-map query dns

To configure Domain Name System (DNS)-based Source Specific Multicast (SSM) mapping, use the ip igmp ssm-map query dns command in global configuration mode. To disable DNS-based SSM mapping, use the no form of this command.

ip igmp ssm-map query dns

no ip igmp ssm-map query dns

Syntax Description

This command has no arguments.

Command Default

This command is enabled by default when the ip igmp ssm-map enable command is enabled.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip igmp ssm-map query dns command.

The following example shows how to disable DNS-based SSM mapping: 

Device(config)# no ip igmp ssm-map query dns

ip load-sharing algorithm

To enable load balancing algorithm on an interface for IPv4, use the ip load-sharing algorithm command in Cisco Catalyst SD-WAN configuration mode. To disable load balancing algorithm on an interface, use the no form of this command.

ip load-sharing algorithm { ip-and-ports | src-dst-ip | src-ip-only }

no ip load-sharing algorithm { ip-and-ports | src-dst-ip | src-ip-only }

Syntax Description

ip-and-ports

Sets the load-balancing algorithm to the include-ports algorithm that uses Layer 4 source and destination ports.

src-dst-ip

Sets the load-balancing algorithm to the src-dst-ip algorithm that uses a source and destination ip.

src-ip-only

Sets the load-balancing algorithm to the src-ip algorithm that uses source ip.

Command Default

src-dst-ip algorithm is enabled by default.

Command Modes

SD-WAN configuration (config-sdwan)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.8.1a

This command was introduced.

Usage Guidelines

When the load-balancing algorithm is set to src-dst-ip mode, each router on the network can make a different load sharing decision for each source-destination address pair.

The ip-and-ports algorithm allows you to use the Layer 4 source and destination ports as part of the load-balancing decision. This method benefits traffic streams running over equal-cost paths that are not loadshared because the majority of the traffic is between peer addresses that use different port numbers, such as Real-Time Protocol (RTP) streams.

The following example shows how to enable load-balancing algorithm for source, destination ip and port:


Device(config)# sdwan
Device(config-sdwan)# ip load-sharing algorithm ip-and-ports

The following example shows how to enable load balancing algorithm for source, destination ip:


Device(config)# sdwan
Device(config-sdwan)# ip load-sharing algorithm src-dst-ip

The following example shows how to enable load balancing algorithm for source ip only:

Device(config)# sdwan
Device(config-sdwan)# ip load-sharing algorithm src-ip-only

ip mtu

To set the maximum transmission unit (MTU) size of IP packets that are sent on an interface, use the ip mtu command in interface configuration mode. To restore the default MTU size, use the no form of this command.

ip mtu bytes

no ip mtu

Syntax Description

bytes

MTU size, in bytes.

Command Default

The default MTU value depends on the interface type.

Table 2. Default MTU Values by Interface Type

Interface Type

Default MTU (Bytes)

ATM

4470

Ethernet

1500

FDDI

4470

High-Speed Serial Interface High Speed Access (HSSI HSA)

4470

Serial

1500

Token Ring

4464

VRF-Aware Service Infrastructure (VASI)

9216

Command Modes

Interface configuration (config-if)
Subinterface configuration (config-subif)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see the IOS XE ip mtu command. 

Device(config)# interface GigabitEthernet 1
Device(config-if)# ip mtu 1500
Device(config)# interface ATM 0/2/0.1 point-to-point
Device(config-if)# ip mtu 1500

ip multicast route-limit

To limit the number of multicast routes (mroutes) that can be added to a multicast routing table, use the ip multicast route-limit command in global configuration mode. To disable this configuration, use the no form of this command.

ip multicast route-limit limit

no ip multicast route-limit limit

Syntax Description

limit

The number of mroutes that can be added. The range is from 1 to 2147483647. The default is 2147483647.

Command Default

limit : 2147483647

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

The ip multicast route-limit command limits the number of multicast routes that can be added to a router and generates an error message when the limit is exceeded.

For usage guidelines, see the Cisco IOS XE ip multicast route-limit command.

The following example shows how to set the mroute limit to 200,000:


Device(config-transaction)# ip multicast route-limit 200000

ip name-server

To specify the address of one or more name servers to use for name and address resolution, use the ip name-server command in global configuration mode. To remove the addresses specified, use the no form of this command.

ip name-server [ vrf | | server-address ]

no ip name-server [ vrf | server-address ]

Syntax Description

vrf

Defines a virtual private network's routing and forwarding instance (VRF) table.

server-address

IPv4 address of a name server.

Command Default

No name server addresses are specified.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip name-server command.

For backward compatibility of Cisco Catalyst SD-WAN Manager Release 20.12.1 with devices running Cisco IOS XE Catalyst SD-WAN Release 17.11.1a, when using CLI device templates or CLI add on feature templates, use a different form of ip name-server command. If ip name-server command is configured in VRF, use the following form of the command:

ip name-server vrf vrf server-ip-list list of DNS servers

If ip name-server command is configured in a global mode, use ip name-server no-vrf list of DNS servers

The following example shows how to specify IPv4 host 10.0.0.0 as the name server: 


Device(config)# ip name-server 10.0.0.0

ip pim

To enable Protocol Independent Multicast (PIM) on an interface, use the ip pim command in interface configuration or virtual network interface configuration mode. To disable PIM on the interface, use the no form of this command.

Supported Parameters

sparse-mode

Enables sparse mode of operation.

Command History

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.5.1a

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

For more information about this command, see the Cisco IOS XE ip pim command. 

ip pim vrf 1 bsr-candidate GigabitEthernet5
ip pim vrf 1 rp-address 172.16.255.116
ip pim vrf 1 rp-candidate GigabitEthernet5 interval 10 priority 5

ip pim sparse-mode

spt-only

ip pim bsr-candidate

To configure a router to announce its candidacy as a bootstrap router (BSR), use the ip pim bsr-candidate command in global configuration mode. To remove this router as a BSR candidate, use the no form of this command.

ip pim [ vrf vrf-name ] bsr-candidate interface-type interface-number [ hash-mask-length [ priority [ accept-rp-candidate [ acl-number | acl-name ] ] ] ]

no ip pim [ vrf vrf-name ] bsr-candidate interface-type interface-number [ hash-mask-length [ priority [ accept-rp-candidate [ acl-number | acl-name ] ] ] ]

Syntax Description

vrf vrf-name

(Optional) Configures the router to announce its candidacy as a BSR for the multicast virtual private network's (MVPN) multicast routing and forwarding instance (MVRF) specified for the vrf-name argument.
interface-type interface-number

Interface type and number of the router from which the BSR address is derived. This address is sent in BSR messages.

Note

 

This interface must be enabled for Protocol-Independent Multicast (PIM) using the ip pim command.

hash-mask-length

(Optional) Length of a mask (32 bits maximum) that is to be combined with the group address before the PIMv2 hash function is called. All the groups with the same seed hash correspond to the same rendezvous point (RP). For example, if this value is 24, only the first 24 bits of the group addresses matter. The hash mask length allows one RP to be used for multiple groups. The default hash mask length is 0.

priority

(Optional) Priority of the candidate BSR (C-BSR). The range is from 0 to 255. The default priority is 0. The C-BSR with the highest priority value is preferred.

Note

 

The Cisco IOS and Cisco IOS XE implementation of PIM BSR uses the value 0 as the default priority for candidate BSRs. This implementation predates RFC 5059, which specifies that 64 be used as the default priority value. The Cisco IOS and Cisco IOS XE implementation, thus, deviates from RFC 5059. To comply with the default priority value specified in the RFC, you must explicitly set the priority value to 64.

accept-rp-candidate

(Optional) Specifies that the C-RP candidate is to be filtered.

acl-number

(Optional) Number of the access control list (ACL) to be used to filter C-RP advertisements. The range is 100 to 199 for standard ACL numbers and 2000 to 2699 for extended ACLs.

Note

 

You must have a valid standard or extended ACL in order to use an ACL in your configuration.

acl-name

(Optional) Name of the ACL to be used to filter C-RP advertisements.

Note

 

You must have a valid standard or extended ACL in order to use an ACL in your configuration.

Command Default

The router is not configured to announce itself as a candidate BSR.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.5.1a

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip pim bsr-candidate command.

The following example shows how to configure the IP address of a router on GigabitEthernet interface 0/0 to be a BSR C-RP with a hash mask length of 0 and a priority of 192: 

Device(config)# ip pim vrf 1 bsr-candidate GigabitEthernet 0/0 0 192

ip pim rp-address

To statically configure the address of a Protocol Independent Multicast (PIM) rendezvous point (RP) for multicast groups, use the ip pim rp-address command in global configuration mode. To remove an RP address, use the no form of this command.

Supported Parameters

vrf vrf-name

(Optional) Specifies that the static group-to-RP mapping be associated with the Multicast Virtual Private Network (MVPN) routing and forwarding (MVRF) instance specified for the vrf-name argument.

rp-address

IP address of the RP to be used for the static group-to-RP mapping. This is a unicast IP address in four-part dotted-decimal notation.

Command History

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.5.1a

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

For more information about this command, see the Cisco IOS XE ip pim rp-address command. 


ip pim vrf 1 bsr-candidate GigabitEthernet5
ip pim vrf 1 rp-address 172.16.255.116
ip pim vrf 1 rp-candidate GigabitEthernet5 interval 10 priority 5

ip pim sparse-mode

spt-only

ip pim rp-candidate

To configure a router to advertise itself to the bootstrap router (BSR) as a Protocol-Indepedenet Multicast (PIM) Version 2 (PIMv2) candidate rendezvous point (C-RP), use the ip pim rp-candidate command in global configuration mode. To remove this router as a C-RP, use the no form of this command.

ip pim [ vrf vrf-name ] rp-candidate interface-type interface-number [ group-list access-list ] [ interval seconds ] [ priority value ]

no ip pim [ vrf vrf-name ] rp-candidate

Syntax Description

vrf vrf-name

(Optional) Configure the router to advertise itself to the BSR as PIMv2 C-RP for the multicast virtual private network's (MVPN) multicast routing and forwarding instance (MVRF) specified for the vrf-name argument.

interface-type interface-number

IP address associated with this interface type and number to be advertised as a C-RP address.

group-list access-list

(Optional) Specifies the standard IP access list number or name that defines the group prefixes that are advertised in association with the RP address. The access list name cannot contain a space or quotation mark, and must begin with an alphabetic character to avoid confusion with numbered access lists.

Note

 

You must have a valid standard or extended ACL in order to use an ACL in your configuration.
interval seconds

(Optional) Specifies the C-RP advertisement interval, in seconds. The range is from 1 to 16383. The default value is 60.

priority value

(Optional) Specifies the priority of the C-RP. The range is from 0 to 255. The default priority value is 0. The BSR C-RP with the lowest priority value is preferred.

Note

 

The Cisco IOS and Cisco IOS XE implementation of PIM BSR uses the value 0 as the default priority for candidate RPs. This implementation predates the draft-ietf-pim-sm-bsr IETF draft, the first IETF draft to specify 192 as the default priority value. The Cisco IOS and Cisco IOS XE implementation, thus, deviates from the IETF draft. To comply with the default priority value specified in the draft, you must explicitly set the priority value to 192.

Command Default

The router is not configured to announce itself to the BSR as a PIMv2 C-RP.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.5.1a

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip pim rp-candidate command.

The following example shows how to configure a router to advertise itself as a C-RP to the BSR in its PIM domain. The standard access list number 4 specifies the group prefix associated with the RP that has the address identified by Gigabit Ethernet interface 0/0. That RP is responsible for the groups with the prefix 239. 

Device(config)# ip pim vrf 1 rp-candidate GigabitEthernet5 interval 10 priority 5
Device(config)# access-list 4 permit 239.0.0.0 0.255.255.255

ip prefix-list

To create a prefix list or to add a prefix list entry, use the ip prefix-list command in global configuration mode. To delete a prefix list entry, use the no form of this command.

ip prefix-list list-name permit network / length

no ip prefix-list list-name permit network / length

Syntax Description

list-name

Name to identify the prefix list. Do not use the words detail or summary as a list name because they are keywords in the show ip prefix-list command.

permit

Permits access for a matching condition.

Command Default

No prefix lists or prefix list entries are created.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1r

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip prefix-list command.

In the following example, a prefix list is configured to permit the default route 10.0.0.0/8: 

Device(config)# ip prefix-list TEST permit 10.0.0.0/8

ip redirects

To enable the task of sending Internet Control Message Protocol (ICMP) redirect messages if the software is forced to resend a packet through the same interface on which it was received, use the ip redirects command in interface configuration mode. To disable the task of sending redirect messages, use the no form of this command.

ip redirects

no ip redirects

Syntax Description

This command has no arguments or keywords.

Command Default

ICMP redirect messages are sent.

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see ip redirects.

The following example shows how to enable the sending of ICMP redirect messages on GigabitEthernet interface 1: 

Device(config)# interface GigabitEthernet 1
Device(config-if)# ip redirects

The following example shows how to disable the sending of ICMP redirect messages on Tunnel interface 1: 

Device(config)# interface Tunnel 1
Device(config-if)# no ip redirects

ip rcmd

To enable the IP remote command (rcmd) option, use the ip rcmd command in global configuration mode. To disable the IP remote command (rcmd) option, use the no form of this command.

ip rcmd { domain-lookup | rcp-enable | rsh-enable }

no ip rcmd { domain-lookup | rcp-enable | rsh-enable }

Syntax Description

domain-lookup

Re-enables basic Domain Name System (DNS) security check for Remote Copy Protocol (RCP) and remote shell (rsh).
rcp-enable

Allows remote users to copy files to and from the router using RCP.
rsh-enable

Allows remote users to execute commands on it using rsh.

Command Default

Domain-lookup is enabled.

rcp-enable is disabled.

rsh-enable is disabled.

Command Modes

Global configuration (config)

Command History

Release Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

The abbreviation RCMD (remote command) is used to indicate both rsh and RCP. DNS lookup for RCMD is enabled by default and is performed as a basic security check. RCP-enable allows a remote user to execute RCP commands on the router. rsh, used as a client process, gives users the ability to remotely get router information, such as status, without the need to connect to the router and then disconnect. RSH-enable enables the router to receive rsh requests from remote users.

The following example shows how to enable RCP and rsh.
Device(config)# ip rcmd rcp-enable
Device(config)# ip rcmd rsh-enable

ip rcmd rcp-enable

To allow remote users to copy files to and from a router using Remote Copy Protocol (RCP), use the ip rcmd rcp-enable command in global configuration mode. To disable RCP on the device, use the no form of this command.

ip rcmd rcp-enable

no ip rcmd rcp-enable

Syntax Description

This command has no arguments or keywords.

Command Default

To ensure security, the router is not enabled for RCP by default.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip rcmd rcp-enable command.

The following example shows how to enable RCP for copying files to and from a router:

Device(config)#ip rcmd rcp-enable

ip rcmd rsh-enable

To configure a router to allow remote users to execute commands on it using remote shell protocol (rsh), use the ip rcmd rsh-enable command in global configuration mode. To disable a router that is enabled for rsh, use the no form of this command.

ip rcmd rsh-enable

no ip rcmd rsh-enable

Syntax Description

This command has no arguments or keywords.

Command Default

To ensure security, the router is not enabled for rsh by default.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip rcmd rsh-enable command.

The following example shows how to enable a router as an rsh server:

Device(config)# ip rcmd rsh-enable

ip route vrf

To establish static routes for a virtual private network's routing and forwarding (VRF) instance, use the ip route vrf command in global configuration mode. To disable static routes, use the no form of this command.

ip route vrf vrf-name prefix mask [ interface interface-number ] [ next-hop-address [ tag tag ] [ track number ] ]

no ip route vrf vrf-name prefix mask [ interface interface-number ] [ next-hop-address [ tag tag ] [ track number ] ]

Syntax Description

vrf-name

Name of the VRF for the static route.

prefix

IP route prefix for the destination, in dotted decimal format.

mask

Prefix mask for the destination, in dotted decimal format.

next-hop-address

(Optional) IP address of the next hop (the forwarding router that can be used to reach that network).

interface

(Optional) Name of network interface to use.

interface-number

(Optional) Number identifying the network interface to use.

tag tag

(Optional) Specifies the label (tag) value that can be used for controlling redistribution of routes through route maps.

track number

(Optional) Associates a track object with this route. Valid values for the number argument range from 1 to 500.

Command Default

No default behavior or values.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Cisco IOS XE Catalyst SD-WAN Release 17.3.1a

Additional parameters qualified: prefix mask for destination address, next-hop address, interface type and number, tag.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip route vrf command. 

Device (config)# ip route vrf 1 192.0.2.1 255.255.255.0 198.51.100.1 track 10 
Device (config)# ip route vrf 1 192.0.2.1 255.255.255.0 198.51.100.1 tag 2 
Device (config)# ip route vrf 1 192.0.2.1 255.255.255.0 198.51.100.1
Device (config)# ip route vrf 1 192.0.2.1 255.255.255.0 GigabitEthernet2
Device (config)# ip route vrf 1 192.0.2.1 255.255.255.0

ip route

To establish a static route, use the ip route command in global configuration mode. To remove static routes, use the no form of this command.

ip route prefix mask [ ip-address | interface-type-interface-number [ip-address] | Null0 | distance ] [ tag tag | track ]

no ip route prefix mask [ ip-address | interface-type-interface-number [ip-address] | Null0 | distance ] [ tag tag | track ]

Syntax Description

prefix

IP route prefix for the destination.

mask

Prefix mask for the destination.

ip-address

IP address of the next hop that can be used to reach the network.

interface-type interface-number

Network interface type and interface number. Valid values for the number argument range from 1 to 500.

track

(Optional) Associates a track object with this route.

tag tag

(Optional) Tag value that can be used as a match value for controlling redistribution through route maps.

Null0

Specifies null0 as the interface to prevent routing loops.

distance

(Optional) Administrative distance. The range is 1 to 255. The default administrative distance for a static route is 1.

Command Default

No static routes are established.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Cisco IOS XE Catalyst SD-WAN Release 17.3.1a

Additional parameters qualified: next-hop-address, Dialer, tag, track, Null0, distance.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip routecommand.

The following example shows how to route packets for network 192.0.2.1 to a router at 198.51.100.1:

ip route 192.0.2.1 255.255.255.0 198.51.100.1
Device(config)# ip route 192.0.2.1 255.255.255.0 198.51.100.1 track <>
ip route 192.0.2.1 255.255.255.0 Dialer2 198.51.100.1 tag <>
ip route 192.0.2.1 255.255.255.0 198.51.100.1 tag <>
ip route 192.0.2.1 255.255.255.0 Dialer2 tag <>
ip route 192.0.2.1 255.255.255.0 Dialer2 198.51.100.1 <>
ip route 192.0.2.1 255.255.255.0 198.51.100.1 <>
ip route 192.0.2.1 255.255.255.0 Dialer2 <>
ip route 192.0.2.1 255.255.255.0 GigabitEthernet2 <>    
ip route 192.0.2.1 255.255.255.0 <>

ip source-route

To allow the Cisco IOS software to handle IP datagrams with source-routing header options, use the ip source-route command in global configuration mode. To have the software discard any IP datagram containing a source-route option, use the no form of this command.

ip source-route

no ip source-route

Syntax Description

This command has no arguments or keywords.

Command Default

Enabled

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

The following example shows how to disable the handling of IP datagrams with source-routing header options:

Device(config)# no ip source-route

ip ssh version

To specify the version of Secure Shell (SSH) to be run on a router, use the ip ssh version command in global configuration mode. To disable the version of SSH that is configured and to return to compatibility mode, use the no form of this command.

ip ssh version 2

no ip ssh version

Syntax Description

2

Router runs only SSH Version 2.

Command Default

If this command is not configured, SSH operates in compatibility mode, that is, Version 1 and Version 2 are both supported.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

Use this command with the keyword 2 to ensure that your router will not inadvertently establish a weaker SSH Version 1 connection.

The following example shows that SSH Version 2 support is configured:


Router (config-transaction)# ip ssh version 2

The following example shows that SSH Version 2 configuration is removed:


Router (config-transaction)# no ip ssh version

ip tcp adjust-mss

To adjust the maximum segment size (MSS) value of TCP synchronize/start (SYN) packets that go through a router, use the ip tcp adjust-mss command in interface configuration mode. To return the MSS value to the default setting, use the no form of this command.

ip tcp adjust-mss max-segment-size

no ip tcp adjust-mss

Syntax Description

max-segment-size

Maximum segment size, in bytes. The range is from 500 to 1460.

Command Default

The MSS is determined by the originating host.

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see ip tcp adjust-mss. 

Device(config)# interface GigabitEthernet 1
Device(config-if)# ip tcp adjust-mss 1100

ip tcp mss

To enable a maximum segment size (MSS) for TCP connections originating or terminating on a router, use the ip tcp mss command in global configuration mode. To disable the configuration of the MSS, use the no form of this command.

ip tcp mss bytes

no ip tcp mss

Syntax Description

bytes

Maximum segment size for TCP connections in bytes. Valid values are from 0 to 10000.

Command Default

This command is disabled.

Command Modes

Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip tcp mass command.

The following example sets the MSS value at 1200: 


Device(config)# ip tcp mss 1200

ip unnumbered

To enable IP processing on an interface without assigning an explicit IP address to the interface, use the ip unnumbered command in interface configuration mode or subinterface configuration mode. To disable the IP processing on the interface, use the no form of this command.

ip unnumbered type

no ip unnumbered

Syntax Description

type

Type of interface. For more information, use the question mark (? ) online help function.

Command Default

Unnumbered interfaces are not supported.

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ip unnumbered command.

The following example shows how to configure GigabitEthernet 1 as an IP unnumbered interface.

Device(config)# interface Tunnel 1
Device(config-if)# ip unnumbered GigabitEthernet1

ip virtual-reassembly

ip virtual-reassemly command is used to enable a virtual packet reassembly on a Cisco IOS XE Catalyst SD-WAN device's interface. Virtual packet reassembly is a mechanism that helps in handling fragmented packets. To disable virtual reassembly, use the no form of this command.

ip virtual-reassembly [max-reassemblies number ] [max-fragments number ] [timeout seconds ] [drop-fragments ]
no ip virtual-reassembly [max-reassemblies number ] [max-fragments number ] [timeout seconds ] [drop-fragments ]

Syntax Description

max-reassemblies

(Optional) The number specifies the maximum number of IP packet reassemblies that can be held in the reassembly queue.

max-fragments

(Optional) The number specifies the upper limit on the number of fragments that can be created from a single IP packet.

timeout

(Optional) The timeout parameter defines the time window during which all fragments belonging to a particular IP packet are expected to arrive.

drop-fragments

(Optional) The drop-fragments parameter allows you to specify how the router should handle alone fragments that do not belong to any active reassembly process.

Command Default

Disabled; all IP directed virtual fragmentation are dropped.

Command Modes

Interface Configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.12.1a Qualified for use in Cisco vManage CLI templates

Example

This example shows how to enable virtual reassemly:


Device# config-transaction
Device(config)#interface GigabitEthernet 3
Device(config-if)#ip virtual-reassembly max-reassemblies 3
Device(config-if)#ip virtual-reassembly max-reassemblies 3 max-fragments 60

ipv6 access-class

To create or configure an IPv6 access class to restrict incoming or outgoing traffic on a virtual terminal line (VTY), use the ipv6 access-class command. To remove the access class, use the no form of this command

ipv6 access-class access-list-name

no ipv6 access-class

Syntax Description

Syntax Description

access-list-name

Name of the IPv6 ACL class. The name can be a maximum of 64 characters. The name can contain characters, numbers, hyphens, and underscores. The name cannot contain a space or quotation mark.

Command Default

None

Command Modes

Line configuration mode (config-line)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 access-class command.

This example shows how to configure an access class on a VTY line:

Device(config)# line vty 0 4
Device(config-line)# ipv6 access-class TEST

ipv6 address

To configure an IPv6 address and enable IPv6 processing on an interface, use the ipv6 address command in interface configuration mode. To remove the address from the interface, use the no form of this command.

ipv6 address ipv6-address

no ipv6 address ipv6-address

Syntax Description

ipv6-address

The IPv6 address to be used.

Command Default

No IPv6 addresses are defined for any interface.

Command Modes


Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For the usage guidelines, see the Cisco IOS ipv6 address command. 

Device(config)# interface GigabitEthernet 1.101
Device(config-if)# ipv6 address 2001:DB8::1

ipv6 address autoconfig

To enable automatic configuration of IPv6 addresses using stateless autoconfiguration on an interface and enable IPv6 processing on the interface, use the ipv6 address autoconfig command in interface configuration mode. To remove the address from the interface, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 address autoconfig command.

The following example assigns the IPv6 address automatically:

Device(config)# interface ethernet 0
Device(config-if)# ipv6 address autoconfig

ipv6 address dhcp client request

To configure an IPv6 client to request a vendor-specific option from a Dynamic Host Configuration Protocol for IPv6 (DHCPv6) server, use the ipv6 address dhcp client request command in interface configuration mode. To remove the request, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 address dhcp client request command.

The following example shows how to configure an interface to request vendor-specific options: 

Device(config)# interface fastethernet 0/0
Device(config-if)# ipv6 address dhcp client request vendor

ipv6 cef load-sharing algorithm

To select a Cisco Express Forwarding load-balancing algorithm for IPv6, use the ipv6 cef load-sharing algorithm command in global configuration mode. To return to the default universal load-balancing algorithm, use the no form of this command.

ipv6 cef load-sharing algorithm { universal [id ] | include-ports [ source [id ] | destination [id ] ] | src-only [id ] }

no ipv6 cef load-sharing algorithm

universal[id]

Sets the load-balancing algorithm to the universal algorithm that uses a source and destination IP. (This is set as default).

id

(Optional) Fixed identifier.

include-ports{source[id] | destination[id]}

Sets the load-balancing algorithm to one that uses the source port and destination port.

src-only [id]

Sets the load-balancing algorithm to include source-only port.

Command Default

The universal load-balancing algorithm is selected. If you do not configure the fixed identifier for a load-balancing algorithm, the router automatically generates a unique ID.

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.6.1a

This command was introduced.

Cisco IOS XE Catalyst SD-WAN Release 17.8.1a

This command was modified. The src-only algorithm is added.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 cef load-sharing algorithm command.

You can enable ECMP keying to send the configurations for both IPv4 and IPv6.

The following example shows how to enable the IPv6 CEF load-balancing algorithm for universal:


Device# config-transaction
Device (config-if)# ipv6 cef load-sharing algorithm universal

The following example shows how to enable the IPv6 CEF load-sharing algorithm for include-ports:


Device# config-transaction
Device(config)# ipv6 cef load-sharing algorithm include-ports source destination

The following example shows how to enable IPv6 CEF load-sharing algorithm to src-only port algorithm:


Device# config-transaction
Device(config)# ipv6 cef load-sharing algorithm src-only

Device(config)# commit

ipv6 dhcp client pd

To enable the Dynamic Host Configuration Protocol (DHCP) for IPv6 client process and enable request for prefix delegation through a specified interface, use the ipv6 dhcp client pd command in interface configuration mode. To disable requests for prefix delegation, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 dhcp client pd command.

The following example enables prefix delegation:

Device(config-if)# ipv6 dhcp client pd dhcp-prefix

The following example configures a hint for prefix-delegating routers:

Device(config-if)# ipv6 dhcp client pd hint 2001:0DB8:1/48

ipv6 dhcp client vendor-class

By default the DHCP client carries PID (Product ID) of the device in option-16. This default behaviour can be overridden by configuring below CLI:

ipv6 dhcp client vendor-class [ mac-address | ascii | | hex | | disable ]

Syntax Description

mac-address

The mac address of the device.

ascii

The user defined string in ascii format.

hex

The user defined string in hexadecimal format.

disable

Disables sending option-16 to DHCP messages.

Command Default

By default option-16 carries PID of the device.

Command Modes


Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.10.1a

This command was introduced.

Usage Guidelines

By default the DHCP client carries PID of the device in option-16. This default behaviour can be overridden by configuring the ipv6 dhcp client vendor-class command.

The following example shows the configuration to override the decive PID with MAC address:


interface GigabitEthernet 0/0/0
    ipv6 address dhcp
    ipv6 dhcp client vendor-class mac-address
    !

The DHCPv6 vendor-class option, overrides the Device PID with MAC Address.

The following example shows the configuration to override the device PID with user defined string in hex or in ascii format:


interface GigabitEthernet 0/0/0
    ipv6 address dhcp
    ipv6 dhcp client vendor-class hex aabbcc
    !


interface GigabitEthernet 0/0/0
    ipv6 address dhcp
    ipv6 dhcp client vendor-class ascii cisco
    !

The following example shows the configuration to disable option-16 in DHCP messages:


interface GigabitEthernet 0/0/0
    ipv6 address dhcp
    ipv6 dhcp client vendor-class disable
    !

ipv6 dhcp pool

To configure a Dynamic Host Configuration Protocol (DHCP) for IPv6 server configuration information pool and enter DHCP for IPv6 pool configuration mode, use the ipv6 dhcp pool command in global configuration mode. To delete a DHCP for IPv6 pool, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 dhcp pool command.

The following example specifies a DHCP for IPv6 configuration information pool named cisco1 and places the router in DHCP for IPv6 pool configuration mode: 

Device(config)# ipv6 dhcp pool cisco1
Device(config-dhcpv6)#

The following example shows how to configure an IPv6 address prefix for the IPv6 configuration pool cisco1: 

Device(config-dhcpv6)# address prefix 2001:1000::0/64

The following example shows how to configure a pool named engineering with three link-address prefixes and an IPv6 address prefix: 

Device(config)#ipv6 dhcp pool engineering
Device(config-dhcpv6)# link-address 2001:1001::0/64
Device(config-dhcpv6)# link-address 2001:1002::0/64
Device(config-dhcpv6)# 
Device(config-dhcpv6)# address prefix 2001:1003::0/64

The following example shows how to configure a pool named 350 with vendor-specific options: 

Device(config)# ipv6 dhcp pool 350
Device(config-dhcpv6)# vendor-specific 9
Device(config-dhcpv6-vs)# suboption 1 address 1000:235D::1
Device(config-dhcpv6-vs)# suboption 2 ascii "IP-Phone"

ipv6 dhcp relay destination

To specify a destination address to which client messages are forwarded and to enable Dynamic Host Configuration Protocol (DHCP) for IPv6 relay service on the interface, use the ipv6 dhcp relay destination command in interface configuration mode. To remove a relay destination on the interface or to delete an output interface for a destination, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 dhcp relay destination command.

The following example sets the relay destination address on Ethernet interface 4/3:

Device(config-if)# ipv6 dhcp relay destination FE80::250:A2FF:FEBF:A056 ethernet 4/3

The following example shows how to set the relay destination address on the Ethernet interface 4/3 on a Cisco CMTS router:

Device(config-if)# ipv6 dhcp relay destination 2001:db8:1234:5678:9abc:def1:2345:6789 ethernet 4/3

ipv6 dhcp-relay option vpn

To enable the DHCP for IPv6 relay VRF-aware feature, use the ipv6 dhcp-relay option vpn command in global configuration mode. To disable the feature, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 dhcp-relay option vpn command.

The following example enables the DHCPv6 relay VRF-aware feature globally on the router:

Device(config)# ipv6 dhcp-relay option vpn

ipv6 dhcp server

To enable Dynamic Host Configuration Protocol (DHCP) for IPv6 service on an interface, use the ipv6 dhcp server in interface configuration mode. To disable DHCP for IPv6 service on an interface, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 dhcp server command.

The following example enables DHCP for IPv6 for the local prefix pool named server1:

Device(config-if)# ipv6 dhcp server server1

ipv6 enable

To enable IPv6 processing on an interface that has not been configured with an explicit IPv6 address, use the ipv6 enable command in interface configuration mode. To disable IPv6 processing on an interface that has not been configured with an explicit IPv6 address, use the no form of this command.

ipv6 enable

no ipv6 enable

Syntax Description

This command has no arguments or keywords.

Command Default

IPv6 is disabled.

Command Modes


Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Release Amsterdam 17.2.1v

Qualified for use in Cisco vManage CLI templates.

Usage Guidelines

The ipv6 enable command automatically configures an IPv6 link-local unicast address on the interface while also enabling the interface for IPv6 processing. The no ipv6 enable command does not disable IPv6 processing on an interface that is configured with an explicit IPv6 address. 

Device(config)# interface GigabitEthernet 1.101
Device(config-if)# ipv6 enable

ipv6 load-sharing algorithm

To enable load balancing algorithm on an interface for IPv6, use the ipv6 load-sharing algorithm command in Cisco Catalyst SD-WAN configuration mode. To disable load balancing algorithm on an interface, use the no form of this command.

ipv6 load-sharing algorithm { ip-and-ports | src-dst-ip | src-ip-only }

no ipv6 load-sharing algorithm { ip-and-ports | src-dst-ip | src-ip-only }

ip-and-ports

Sets the load-balancing algorithm to the include-ports algorithm that uses Layer 4 source and destination ports.

src-dst-ip

Sets the load-balancing algorithm to the src-dst-ip algorithm that uses a source and destination ip.

src-ip-only

Sets the load-balancing algorithm to the src-ip algorithm that uses source ip.

Command Default

src-dst-ip algorithm is enabled by default.

Command Modes

SD-WAN configuration (config-sdwan)

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.8.1a

This command was introduced.

Usage Guidelines

When the load-balancing algorithm is set to src-dst-ip mode, each router on the network can make a different load sharing decision for each source-destination address pair.

The ip-and-ports algorithm allows you to use the Layer 4 source and destination ports as part of the load-balancing decision. This method benefits traffic streams running over equal-cost paths that are not loadshared because the majority of the traffic is between peer addresses that use different port numbers, such as Real-Time Protocol (RTP) streams.

The following example shows how to enable load-balancing algorithm for source, destination ip and port:


Device(config)# sdwan
Device(config-sdwan)# ipv6 load-sharing algorithm ip-and-ports

The following example shows how to enable load balancing algorithm for source, destination ip:


Device(config)# sdwan
Device(config-sdwan)# ipv6 load-sharing algorithm src-dst-ip

The following example shows how to enable load balancing algorithm for source ip only:

Device(config)# sdwan
Device(config-sdwan)# ipv6 load-sharing algorithm src-ip-only

ipv6 nd other-config-flag

To set the "other stateful configuration" flag in IPv6 router advertisements, use the ipv6 nd other-config-flag command in interface configuration mode. To clear the flag from IPv6 router advertisements, use the no form of this command.

ipv6 nd other-config-flag

no ipv6 nd other-config-flag

Command Default

None

Command Modes

interface configuration (config-if)

Command History

Release Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

The setting of the "other stateful configuration" flag in IPv6 router advertisements indicates to attached hosts how they can obtain autoconfiguration information other than addresses. If the flag is set, the attached hosts should use stateful autoconfiguration to obtain the other (nonaddress) information.

Example

The following example configures the “other stateful configuration” flag in ipv6 router advertisements on GigabitEthernet 0/0/2. 

Device(config)# interface GigabitEthernet 0/0/2
Device(config-if)# ipv6 nd other-config-flag
Table 3. Related Commands

Command

Description
ipv6 nd managed-config-flag

Sets the “managed address configuration” flag in ipv6 router advertisements.

ipv6 nd prefix

To configure ipv6 prefixes that are included in IPv6 neighbor discovery router advertisements, use the ipv6 nd prefix command in interface configuration mode. To remove the prefixes, use the no form of this command.

ipv6 nd prefix ipv6-prefix /prefix-length [ no-advertise ]

no ipv6 nd prefix ipv6-prefix /prefix-length [ no-advertise ]

Syntax Description

ipv6-prefix

Specifies the ipv6 network number to include the router advertisements (RA).
/ prefix-length

Specifies the length of the ipv6 prefix.
no-advertise

(Optional) specifies that the prefix is not advertised.

Command Default

All prefixes configured on interfaces that originate IPv6 router advertisements are advertised with a valid lifetime of 2,592,000 seconds (30 days) and a preferred lifetime of 604,800 seconds (7 days).

Command Modes

Interface configuration (config-if)

Command History

Release Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

The ipv6 nd prefix command allows control over individual parameters per prefix, including whether the prefix should be advertised or not.

Example

The following example includes the ipv6 prefix 2001:0DB8::/35 in router advertisements sent out GigabitEthernet 0/0/2.

Device(config)# interface GigabitEthernet 0/0/2
Device(config-if)# ipv6 nd prefix 2001:0DB8::/35

ipv6 nd ra suppress

To suppress IPv6 router advertisement transmissions on an interface, use the ipv6 nd ra suppress command in interface configuration mode. To reenable the sending of IPv6 router advertisement transmissions on an interface, use the no form of this command.

ipv6 nd ra suppress [ all ]

no ipv6 nd ra suppress [ all ]

Syntax Description

all

(optional) suppress all router advertisements (RAs) on an interface.

Command Default

IPv6 router advertisements are automatically sent on Ethernet and FDDI interfaces if IPv6 unicast routing is enabled on the interfaces. IPv6 router advertisements are not sent on other types of interfaces.

Command Modes

Interface configuration (config-if)

Command History

Release Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

The ipv6 nd ra suppress command only suppresses periodic unsolicited RAs. It does not suppress RAs sent in response to a router solicitation. To suppress all RAs, including those sent in response to a router solicitation, use the ipv6 nd ra suppress command with the all keyword.

Example

The following example shows how to suppress IPv6 router advertisements on interface GigabitEthernet 0/0/2.

Device(config)# interface GigabitEthernet 0/0/2
Device(config-if)# ipv6 nd ra suppress
Table 4. Related Commands

Command

Description
show ipv6 interface

Displays the usability status of interfaces configured for IPv6.

ipv6 nd router-preference

To configure a default router preference (DRP) for the router on a specific interface, use the ipv6 nd router-preference command in interface configuration mode. To return to the default DRP, use the no form of this command.

ipv6 nd router-preference { high | medium | low }

no ipv6 nd router-preference { high | medium | low }

Syntax Description

high

Preference for the router specified on an interface is high.
medium

Preference for the router specified on an interface is medium.
low

Preference for the router specified on an interface is low.

Command Default

Router Advertisements (RAs) are sent with the medium preference.

Command Modes

Interface configuration (config-if)

Command History

Release Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco SD-WAN Manager CLI templates.

Usage Guidelines

Router Advertisement messages are sent with the DRP configured by the ipv6 nd router-preference command. If no DRP is configured, Router Advertisements are sent with a medium preference. A DRP is useful when, for example, two routers on a link may provide equivalent, but not equal-cost, routing, and policy may dictate that hosts should prefer one of the routers.

Example

The following example configures a DRP of high for the router on GigabitEthernet 0/0/2.

Device(config)# interface GigabitEthernet 0/0/2
Device(config-if)# ipv6 nd router-preference High

ipv6 redirects

To enable the sending of Internet Control Message Protocol (ICMP) IPv6 redirect messages if Cisco IOS software is forced to resend a packet through the same interface on which the packet was received, use the ipv6 redirects command in interface configuration mode. To disable the sending of redirect messages, use the no form of this command.

ipv6 redirects

no ipv6 redirects

Syntax Description

This command has no arguments or keywords.

Command Default

The sending of ICMP IPv6 redirect messages is enabled.

Command Modes

Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

The following example disables the sending of ICMP IPv6 redirect messages on Tunnel interface 1: 

Device(config)# interface Tunnel 1
Device(config-if)# ipv6 unnumbered GigabitEthernet0/2.101
Device(config-if)# no ipv6 redirects

Related Commands

Command

Description

ipv6 icmp error-interval

Configures the interval for IPv6 ICMP error messages.

ipv6 route

To establish static IPv6 routes, use the ipv6 route command in global configuration mode. To remove a previously configured static route, use the no form of this command.

ipv6 route vrf vrf-name ipv6-prefix/prefix-length

no ipv6 route vrf vrf-name ipv6-prefix/prefix-length

Syntax Description

ipv6-prefix

The IPv6 network that is the destination of the static route. Can also be a host name when static host routes are configured.

/ prefix-length

The length of the IPv6 prefix. A decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address). A slash mark must precede the decimal value.

vrf vrf-name

Specifies all virtual private network (VPN) routing/forwarding instance (VRF) tables or a specific VRF table for an IPv6 address.

Command Default

No static routes are established.

Command Modes


Global configuration

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE ipv6 route command.

The following example configures a static route for use in a VRF for IPv6: 

ipv6 route vrf TEST 2001:DB8::/32

ipv6-strict-control

To configure IPv6 as a default option on Cisco IOS XE Catalyst SD-WAN devices, Cisco SD-WAN Manager, and Cisco Catalyst SD-WAN Controller, use the ipv6-strict-control command in system configuration mode. To remove the option from the interface, use the no form of this command.

ipv6-strict-control { true | false }

no ipv6-strict-control

Syntax Description

true

Enables IPv6 as the default connection option for connecting to Cisco SD-WAN Manager, Cisco Catalyst SD-WAN Controller, and Cisco IOS XE Catalyst SD-WAN devices.

Command Default

An IPv4 connection is defined for an interface.

Command Modes

System configuration (config-system)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.10.1a

Qualified for use in Cisco SD-WAN Manager CLI templates.

The following example shows how to configure IPv6 as a default connection option on a Cisco IOS XE Catalyst SD-WAN device to connect to Cisco SD-WAN Manager and Cisco Catalyst SD-WAN Controller: 

Device(config)# system                                                                                                                              
Device(config-system)# gps-location latitude 32.0                                                                                                   
Device(config-system)# gps-location longitude -100.0                                                                                                
Device(config-system)# system-ip 10.16.255.14                                                                                                       
Device(config-system)# domain-id 1                                                                                                                  
Device(config-system)# site-id 400                                                                                                                  
Device(config-system)# ipv6-strict-control true                                                                                                     
Device(config-system)# admin-tech-on-failure                                                                                                        
Device(config-system)# organization-name "Cisco"                                                                                                    
Device(config-system)# vbond vbond

ipv6 unnumbered

To enable IPv6 processing on an interface without assigning an explicit IPv6 address to the interface, use the ipv6 unnumbered command in interface configuration mode. To disable IPv6 on an unnumbered interface, use the no form of this command.

ipv6 unnumbered interface-type interface-number

no ipv6 unnumbered

Syntax Description

interface-type

The interface type of the source address that the unnumbered interface uses in the IPv6 packets that it originates. The source address cannot be another unnumbered interface.

interface-number

The interface number of the source address that the unnumbered interface uses in the IPv6 packets that it originates.

Command Default

This command is disabled.

Command Modes


Interface configuration (config-if)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

IPv6 packets that are originated from an unnumbered interface use the global IPv6 address of the interface specified in the ipv6 unnumbered command as the source address for the packets. The ipv6 unnumbered interface command is used as a hint when doing source address selection; that is, when trying to determine the source address of an outgoing packet. 

Device(config)# interface Tunnel 1
Device(config-if)# ipv6 unnumbered GigabitEthernet0/2.101

lease

To configure the duration of the lease for an IP address that is assigned from a Cisco IOS Dynamic Host Configuration Protocol (DHCP) server to a DHCP client, use the lease command in DHCP pool configuration mode. To restore the default value, use the no form of this command.

lease days [ hours [minutes] ]

no lease

Syntax Description

days

Specifies the duration of the lease in numbers of days.

hours

(Optional) Specifies the number of hours in the lease. A days value must be supplied before you can configure an hours value.

minutes

(Optional) Specifies the number of minutes in the lease. A days value and an hours value must be supplied before you can configure a minutes value.

infinite

Specifies that the duration of the lease is unlimited.

Command Default

1 day

Command Modes

DHCP pool configuration (dhcp-config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

The following example shows a 365 day lease:

Device (config)# ip dhcp pool POOL1
Device(dhcp-config)# lease 365 0 0

network (DHCP)

To configure the network number and mask for a Dynamic Host Configuration Protocol (DHCP) address pool primary subnet on a DHCP server, use the network command in DHCP pool configuration mode. To remove the subnet number and mask, use the no form of this command.

network network-number [mask]

Syntax Description

network-number

The IP address of the primary DHCP address pool.

mask

(Optional) The bit combination that renders which portion of the address of the DHCP address pool refers to the network or subnet and which part refers to the host.

Command Default

This command is disabled by default.

Command Modes

DHCP pool configuration (dhcp-config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE network (DHCP) command.

The following example shows how to configure 255.255.255. 0 as the subnetwork number and mask of the DHCP pool named pool1. 


Device(config)# ip dhcp pool pool1
Device(dhcp-config)# network 172.16.0.0 255.255.255.0

option (DHCP)

To configure DHCP server options, use the option command in DHCP pool configuration mode. To remove the options, use the no form of this command.

option code [ ip list-name ]

no option code

Syntax Description

code

Specifies the DHCP option code. The range is from 0 to 254.

ip address

Specifies an IP address. Up to eight IP addresses can be specified.

string

Hexadecimal value truncated to 180 characters entered. Each byte in hexadecimal character strings is two hexadecimal digits. Each byte can be separated by a period, colon, or white space.

Command Default

The default instance number is 0.

Command Modes

DHCP pool configuration (dhcp-config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

The following example shows how to configure DHCP option 150 for an IP list containing two IP addresses.


Device(config)# ip dhcp pool POOL1
Device(dhcp-config)# option 150 ip 10.10.10.1 10.10.10.2

prefix-delegation

To specify a manually configured numeric prefix to be delegated to a specified client (and optionally a specified identity association for prefix delegation [IAPD] for that client), use the prefix-delegation command in DHCP for IPv6 pool configuration mode. To remove the prefix, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE prefix-delegation command.

The following example configures an IAPD for a specified client: 

Device(config)# prefix-delegation 2001:0DB8::/64 00030001000BBFAA2408

prefix-delegation pool

To specify a named IPv6 local prefix pool from which prefixes are delegated to Dynamic Host Configuration Protocol (DHCP) for IPv6 clients, use the prefix-delegation pool command in DHCP for IPv6 pool configuration mode. To remove a named IPv6 local prefix pool, use the no form of this command.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE prefix-delegation pool command.

The following example specifies that prefix requests should be satisfied from the pool called client-prefix-pool. The prefixes should be delegated with the valid lifetime set to 1800 seconds, and the preferred lifetime is set to 600 seconds: 

Device(config)# prefix-delegation pool client-prefix-pool lifetime 1800 600

spt-only

To configure multicast routing in Cisco SD-WAN to use shortest-path first trees (SPT) only, use the spt-only command in VRF configuration mode. To disable SPT-only use the no form of this command.

spt-only

no spt-only

This command has no keywords or arguments.

Command Default

SPT-only is not configured.

Command Modes

VRF configuration (config-vrf-<vrf-id>)

Command History

Release Modification
Cisco IOS XE Catalyst SD-WAN Release 17.5.1a

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

Enable spt-only on all Cisco IOS XE SD-WAN devices that have Cisco SD-WAN multicast overlay configured for the VRF.

Example

Device(config)# sdwan multicast address-family ipv4 vrf 1 
Device(config-vrf-1)# spt-only

vlan internal allocation policy

To configure the allocation direction of the internal VLAN, use the vlaninternalallocationpolicy command in global configuration mode. To return the default setting, use the no form of this command to return.

vlan internal allocation policy ascending

no vlan internal allocation policy

Syntax Description

ascending

Allocates internal VLANs from 1006 to 4094.

Command Default

ascending

Command Modes

Global configuration (config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE vlan internal allocation policy command. 


Device(config)# vlan internal allocation policy ascending

vendor-specific

To configures vendor-defined options for the IPv6 address pool, use the vendor-specific command in global configuration mode. To disable the feature, use the no form of this command.

vendor-specific vendor-id

Syntax Description

vendor-id

Specify an ID for the vendor.

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.7.1a

This command was introduced.

The following example configures vendor-defined options for the IPv6 address pool:

Device(config)# vendor-specific 10

vrf (DHCP pool)

To associate the on-demand address pool with a VPN routing and forwarding instance (VRF) name, use the vrf command in DHCP pool configuration mode. To remove the VRF name, use the no form of this command.

vrf name

no vrf name

Syntax Description

name

Name of the VRF to which the address pool is associated.

Command Default

No default behavior or values

Command Modes

DHCP pool configuration (dhcp-config)

Command History

Release

Modification

Cisco IOS XE Catalyst SD-WAN Release 17.2.1v

Command qualified for use in Cisco vManage CLI templates.

Usage Guidelines

For usage guidelines, see the Cisco IOS XE vrf (DHCP Pool)command.

The following example associates the address pool with a VRF named TEST:

Device(config)# ip dhcp pool POOL1
Device(dhcp-config)# vrf TEST