Contents
- OSPF Support for MTR
- Finding Feature Information
- Prerequisites for OSPF Support for MTR
- Information About OSPF Support for MTR
- Routing Protocol Support for MTR
- Interface Configuration Support for MTR
- How to Configure OSPF Support for MTR
- Activating an MTR Topology by Using OSPF
- What to Do Next
- Activating an MTR Topology in Interface Configuration Mode by Using OSPF
- Monitoring Interface and Topology IP Traffic Statistics for MTR
- Configuration Examples for OSPF Support for MTR
- Examples: Activating an MTR Topology by Using OSPF
- Examples: MTR OSPF Topology in Interface Configuration Mode
- Additional References
- Feature Information for OSPF Support for MTR
OSPF Support for MTR
The OSPF Support for MTR feature provides Open Shortest Path First (OSPF) support for multiple logical topologies over a single physical network. This module describes how to configure OSPF for Multitopology Routing (MTR).
- Finding Feature Information
- Prerequisites for OSPF Support for MTR
- Information About OSPF Support for MTR
- How to Configure OSPF Support for MTR
- Configuration Examples for OSPF Support for MTR
- Additional References
- Feature Information for OSPF Support for MTR
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for OSPF Support for MTR
Be familiar with the concepts documented in the“ Routing Protocol Support for MTR” section.
Configure and activate a global topology configuration.
Check your Open Shortest Path First (OSPF) device configuration and enter the topology-aware device configuration commands in router address family configuration mode.
Several OSPF configuration commands need to be topology-aware. Before you configure OSPF Multitopology Routing (MTR), you need to enter the following commands in router address family configuration mode if they are used in your original OSPF device configuration. - area area-id default-cost cost
- area area-id filter-list prefix prefix-list-name {in | out}
- area nssa area-id [no-redistribution] [default-information-originate [metric] [metric-type] [no-summary] [nssa-only]
- area area-id range ip-address mask [advertise | not-advertise] [cost cost]
- area area-id stub [no-summary]
- area transit-area-id virtual-link transit-router-id topology disable
- default-information originate [always] [metric metric-value] [metric-type type-value] [route-map map-name]
- default-metric metric-value
- discard-route [external | internal]
- distance ospf {external dist1 | inter-area dist2 | intra-area dist3}
- distribute-list in
- distribute-list out
- max-metric router-lsa [on-startup {seconds | wait-for-bgp}]
- maximum-paths number-of-paths
- neighbor ip-address [cost number]
- redistribute protocol [process-id] {level-1 | level-1-2 | level-2} [as-number] [metric {metric-value | transparent}] [metric-type type-value] [match {external | internal | nssa-external}] [tag tag-value] [route-map map-tag] [subnets]
- summary-address {ip-address mask | prefix mask} [not-advertise] [tag tag]
- timers throttle spf spf-start spf-hold spf-max-wait
- traffic-share min across-interfaces
Information About OSPF Support for MTR
Routing Protocol Support for MTR
You must enable IP routing on the device for Multitopology Routing (MTR) to operate. MTR supports static and dynamic routing in Cisco software. You can enable dynamic routing per topology to support interdomain and intradomain routing. Route calculation and forwarding are independent for each topology. MTR support is integrated into Cisco software for the following protocols:
Border Gateway Protocol (BGP)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Integrated Intermediate System-to-Intermediate System (IS-IS)
Open Shortest Path First (OSPF)
You apply the per-topology configuration in router address family configuration mode of the global routing process (router configuration mode). The address family and subaddress family are specified when the device enters address family configuration mode. You specify the topology name and topology ID by entering the topology command in address family configuration mode.
You configure each topology with a unique topology ID under the routing protocol. The topology ID is used to identify and group Network Layer Reachability Information (NLRI) for each topology in updates for a given protocol. In OSPF, EIGRP, and IS-IS, you enter the topology ID during the first configuration of the topology command for a class-specific topology. In BGP, you configure the topology ID by entering the bgp tid command under the topology configuration.
You can configure class-specific topologies with different metrics than the base topology. Interface metrics configured on the base topology can be inherited by the class-specific topology. Inheritance occurs if no explicit inheritance metric is configured in the class-specific topology.
You configure BGP support only in router configuration mode. You configure Interior Gateway Protocol (IGP) support in router configuration mode and in interface configuration mode.
By default, interfaces are not included in nonbase topologies. For routing protocol support for EIGRP, IS-IS, and OSPF, you must explicitly configure a nonbase topology on an interface. You can override the default behavior by using the all-interfaces command in address family topology configuration mode. The all-interfaces command causes the nonbase topology to be configured on all interfaces of the device that are part of the default address space or the virtual routing and forwarding (VRF) instance in which the topology is configured.
Interface Configuration Support for MTR
The configuration of a Multitopology Routing (MTR) topology in interface configuration mode allows you to enable or disable MTR on a per-interface basis. By default, a class-specific topology does not include any interfaces.
You can include or exclude individual interfaces by configuring the topology interface configuration command. You specify the address family and the topology (base or class-specific) when entering this command. The subaddress family can be specified. If no subaddress family is specified, the unicast subaddress family is used by default.
You can include globally all interfaces on a device in a topology by entering the all-interfaces command in routing topology configuration mode. Per-interface topology configuration applied with the topology command overrides global interface configuration.
The interface configuration support for MTR has these characteristics:
Per-interface routing configuration: Interior Gateway Protocol (IGP) routing and metric configurations can be applied in interface topology configuration mode. Per-interface metrics and routing behaviors can be configured for each IGP.
Open Shortest Path First (OSPF) interface topology configuration: Interface mode OSPF configurations for a class-specific topology are applied in interface topology configuration mode. In this mode, you can configure an interface cost or disable OSPF routing without removing the interface from the global topology configuration.
Enhanced Interior Gateway Routing Protocol (EIGRP) interface topology configuration: Interface mode EIGRP configurations for a class-specific topology are applied in interface topology configuration mode. In this mode, you can configure various EIGRP features.
Intermediate System-to-Intermediate System (IS-IS) interface topology configuration: Interface mode IS-IS configurations for a class-specific topology are applied in interface topology configuration mode. In this mode, you can configure an interface cost or disable IS-IS routing without removing the interface from the global topology configuration.
How to Configure OSPF Support for MTR
Activating an MTR Topology by Using OSPF
Note | Only Multitopology Routing (MTR) commands are shown in this task. |
1.
enable
2.
configure terminal
3.
router ospf
process-id [vrf
vrf-name]
4.
address-family ipv4 [multicast |
unicast]
5.
topology {base |
topology-name
tid
number}
6.
end
7.
show ip ospf [process-id]
topology-info [multicast] [topology {topology-name |
base}]
DETAILED STEPS
What to Do Next
If an Enhanced Interior Gateway Routing Protocol (EIGRP) topology configuration is required, see the “EIGRP Support for MTR” feature module.
If an Intermediate System-to-Intermediate System (IS-IS) topology configuration is required, see the “IS-IS Support for MTR” feature module.
Activating an MTR Topology in Interface Configuration Mode by Using OSPF
Define a topology globally before performing the per-interface topology configuration.
1.
enable
2.
configure terminal
3.
interface
type number
4.
topology ipv4 [multicast |
unicast] {topology-name [disable] |
base}
5.
ip ospf cost
number
6.
ip ospf topology disable
7.
end
8.
show ip ospf [process-id]
interface [type number] [brief] [multicast] [topology {topology-name |
base}]
DETAILED STEPS
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. | ||
Step 2 |
configure terminal
Example: Device# configure terminal |
Enters global configuration mode. | ||
Step 3 |
interface
type number
Example: Device(config)# interface Ethernet 0/0 |
Specifies the interface type and number, and enters interface configuration mode. | ||
Step 4 |
topology ipv4 [multicast |
unicast] {topology-name [disable] |
base}
Example: Device(config-if)# topology ipv4 VOICE |
Enters interface topology configuration mode to configure Multitopology Routing (MTR).
| ||
Step 5 |
ip ospf cost
number
Example: Device(config-if-topology)# ip ospf cost 100 |
Applies a cost to the interface in a topology instance. | ||
Step 6 |
ip ospf topology disable
Example: Device(config-if-topology)# ip ospf topology disable |
Prevents Open Shortest Path First (OSPF) from advertising the interface as part of the topology without disabling the OSPF process or the topology on the interface. | ||
Step 7 |
end
Example: Device(config-if-topology)# end |
Exits interface topology configuration mode and returns to privileged EXEC mode. | ||
Step 8 |
show ip ospf [process-id]
interface [type number] [brief] [multicast] [topology {topology-name |
base}]
Example: Device# show ip ospf 1 interface topology VOICE |
(Optional) Displays OSPF-related interface information. |
Monitoring Interface and Topology IP Traffic Statistics for MTR
Use any of the following commands in any order to monitor interface and topology IP traffic statistics for Multitopology Routing (MTR).
1.
enable
2.
show ip interface [type number] [topology {name |
all |
base}] [stats]
3.
show ip traffic [topology {name |
all |
base}]
4.
clear ip interface
type number [topology {name |
all |
base}] [stats]
5.
clear ip traffic [topology {name |
all |
base}]
DETAILED STEPS
Command or Action | Purpose | |
---|---|---|
Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
Step 2 |
show ip interface [type number] [topology {name |
all |
base}] [stats]
Example: Device# show ip interface FastEthernet 1/10 stats |
(Optional) Displays IP traffic statistics for all interfaces or statistics related to the specified interface.
|
Step 3 |
show ip traffic [topology {name |
all |
base}]
Example: Device# show ip traffic topology VOICE |
(Optional) Displays global IP traffic statistics (an aggregation of all the topologies when MTR is enabled) or statistics related to a particular topology. |
Step 4 |
clear ip interface
type number [topology {name |
all |
base}] [stats]
Example: Device# clear ip interface FastEthernet 1/10 topology all |
(Optional) Resets interface-level IP traffic statistics. |
Step 5 |
clear ip traffic [topology {name |
all |
base}]
Example: Device# clear ip traffic topology all |
(Optional) Resets IP traffic statistics. |
Configuration Examples for OSPF Support for MTR
Examples: Activating an MTR Topology by Using OSPF
The following example shows how to configure the VOICE topology in an Open Shortest Path First (OSPF) routing process and set the priority of the VOICE topology to the highest priority:
router ospf 1 address-family ipv4 topology VOICE tid 10 priority 127 end
In the following example, the show ip ospf command is used with the topology-info and topology keywords to display OSPF information about the topology named VOICE:
Device# show ip ospf 1 topology-info topology VOICE OSPF Router with ID (10.0.0.1) (Process ID 1) VOICE Topology (MTID 66) Topology priority is 64 Redistributing External Routes from, isis Number of areas transit capable is 0 Initial SPF schedule delay 5000 msecs Minimum hold time between two consecutive SPFs 10000 msecs Maximum wait time between two consecutive SPFs 10000 msecs Area BACKBONE(0) (Inactive) SPF algorithm last executed 16:45:18.984 ago SPF algorithm executed 3 times Area ranges are Area 1 SPF algorithm last executed 00:00:21.584 ago SPF algorithm executed 1 times Area ranges are
Examples: MTR OSPF Topology in Interface Configuration Mode
The following example shows how to disable Open Shortest Path First (OSPF) routing on Ethernet interface 0/0 without removing the interface from the global topology configuration:
interface Ethernet 0/0 topology ipv4 VOICE ip ospf cost 100 ip ospf topology disable end
In the following example, the show ip ospf interface command is used with the topology keyword to display information about the topologies configured for OSPF in interface configuration mode:
Device# show ip ospf 1 interface topology VOICE VOICE Topology (MTID 66) Serial3/0 is up, line protocol is up Internet Address 10.0.0.5/30, Area 1 Process ID 1, Router ID 44.44.44.44, Network Type POINT_TO_POINT Topology-MTID Cost Disabled Shutdown Topology Name 4 77 no no grc Transmit Delay is 1 sec, State POINT_TO_POINT Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 oob-resync timeout 40 Hello due in 00:00:05 Supports Link-local Signaling (LLS) Cisco NSF helper support enabled IETF NSF helper support enabled Index 1/4, flood queue length 0 Next 0x0(0)/0x0(0) Last flood scan length is 1, maximum is 1 Last flood scan time is 0 msec, maximum is 0 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 10.2.2.2 Suppress hello for 0 neighbor(s)
In the following example, the show ip ospf interface command is used with the brief and topology keywords to display information about the topologies configured for OSPF in interface configuration mode:
Device# show ip ospf 1 interface brief topology VOICE VOICE Topology (MTID 66) Interface PID Area IP Address/Mask Cost State Nbrs F/C Se3/0 1 1 10.0.0.5/30 1 UP 0/0 Se2/0 1 1 10.0.0.1/30 1 UP 0/0
Additional References
Related Documents
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
Multitopology Routing (MTR) commands |
|
Open Shortest Path First (OSPF) commands |
|
OSPF concepts and tasks |
IP Routing: OSPF Configuration Guide |
Technical Assistance
Description |
Link |
---|---|
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Feature Information for OSPF Support for MTR
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
---|---|---|
OSPF Support for MTR |
12.2(33)SRB |
This feature provides Open Shortest Path First (OSPF) support for multiple logical topologies over a single physical network. The following commands were introduced or modified: address-family ipv4, area capability default-exclusion, ip ospf cost, ip ospf topology disable, priority, router ospf, show ip ospf interface, show ip ospf topology-info, topology. |