IP Unnumbered Ethernet Polling Support

The IP Unnumbered Ethernet Polling Support feature provides IP unnumbered support for Ethernet physical interfaces. This support already exists for serial interfaces.

Information About IP Unnumbered Ethernet Polling Support

IP Unnumbered Ethernet Polling Support Overview

IP unnumbered support for serial interfaces is extended to Ethernet physical interfaces. Unnumbered Ethernet physical interfaces are used in the same manner as unnumbered serial interfaces. On a device, if a loopback interface is configured and an IP address is assigned to it, using the polling option more than one Ethernet physical interface can be unnumbered to the loopback.

The polling option enables the dynamic discovery of hosts (connected though the unnumbered interfaces) based on the Address Resolution Protocol (ARP) protocol.

How to Configure IP Unnumbered Ethernet Polling Support

Enabling Polling on an Ethernet Interface

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface type number
  4. ip address ip-address mask
  5. exit
  6. interface type number
  7. ip unnumbered type number poll
  8. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

interface type number

Example:


Device(config)# interface loopback 0

Specifies an interface and enters interface configuration mode.

Step 4

ip address ip-address mask

Example:


Device(config-if)# ip address 209.165.200.229 255.255.240.224

Configures the IP address on the interface.

Step 5

exit

Example:


Device(config-if)# exit

Exits interface configuration mode and returns to global configuration mode.

Step 6

interface type number

Example:


Device(config)# interface ethernet 0/0

Specifies an interface and enters interface configuration mode.

Step 7

ip unnumbered type number poll

Example:


Device(config-if)# ip unnumbered loopback 0 poll

Enables IP–connected host polling on the specified interface.

Step 8

end

Example:


Device(config-if)# end

Returns to privileged EXEC mode.

Configuring the Queue Size and the Packet Rate for IP ARP Polling for Unnumbered Interfaces

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ip arp poll queue queue-size
  4. ip arp poll rate packet-rate
  5. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

ip arp poll queue queue-size

Example:


Device(config)# ip arp poll queue 1000

Configures the IP ARP polling queue size.

Step 4

ip arp poll rate packet-rate

Example:


Device(config)# ip arp poll rate 1000

Configures the IP ARP polling packet rate, in packets per second.

Step 5

end

Example:


Device(config-if)# end

Returns to privileged EXEC mode.

Verifying IP Unnumbered Ethernet Polling Support

Perform this task to verify IP unnumbered Ethernet polling support.


Note

The show commands are not in any specific order.

SUMMARY STEPS

  1. enable
  2. show ip arp poll
  3. show ip interface type number unnumbered
  4. show ip interface type number unnumbered detail

DETAILED STEPS

Step 1

enable

Enables privileged EXEC mode.

Example:

Device> enable

Step 2

show ip arp poll

Displays the IP ARP host polling status.

Example:

Device# show ip arp poll

Number of IP addresses processed for polling: 438
Number of entries in the queue: 100 (high water mark: 154, max: 1000)
Number of request dropped:
  Queue was full: 1288
  Request was throttled by incomplete ARP: 10
  Duplicate entry found in queue: 1431

Step 3

show ip interface type number unnumbered

Displays the status of unnumbered interface support on interfaces configured for IP.

Example:

Device# show ip interface loopback 0 unnumbered

Number of unnumbered interfaces with polling: 10
Number of IP addresses processed for polling: 15
Number of IP addresses in queue for polling: 4

Step 4

show ip interface type number unnumbered detail

Displays the detailed status of unnumbered interface support on interfaces configured for IP.

Example:

Device# show ip interface loopback 0 unnumbered detail

Number of unnumbered interfaces with polling: 10
Number of IP addresses processed for polling: 15
Last 10 IP addresses processed for polling:
  209.165.201.2
  209.165.201.3
  209.165.201.4
  209.165.201.5
  209.165.201.6
  209.165.201.7
  209.165.201.8
  209.165.201.9
  209.165.201.10
  209.165.201.11
Number of IP addresses in queue for polling: 4 (high water mark: 5)
  209.165.201.12
  209.165.201.13
  209.165.201.14
  209.165.201.15

Configuration Examples for IP Unnumbered Ethernet Polling Support

Example: Enabling Polling on an Ethernet Interface

Device> enable
Device# configure terminal
Device(config)# interface loopback 0
Device(config-if)# ip address 209.165.200.229 255.255.240.224
Device(config-if)# exit
Device(config)# interface ethernet 0/0
Device(config-if)# ip unnumbered loopback 0 poll
Device(config-if)# end

Example: Configuring the Queue Size and the Packet Rate for IP ARP Polling for Unnumbered Interfaces

Device> enable
Device# configure terminal
Device(config)# ip arp poll queue 1000
Device(config)# ip arp poll rate 1000
Device(config)# end

Additional References

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

IPv4 Addressing commands

Cisco IOS IP Addressing Services Command Reference

Conceptual information about IPv4 addresses

“Configuring IPv4 Addresses” module in the IP Addressing: IPv4 Addressing Configuration Guide

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for IP Unnumbered Ethernet Polling Support

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.
Table 1. Feature Information for IP Unnumbered Ethernet Polling Support

Feature Name

Releases

Feature Information

IP Unnumbered Ethernet Polling Support

Cisco IOS XE Release 3.8S

The IP Unnumbered Ethernet Polling Support feature provides IP unnumbered support for Ethernet physical interfaces.

The following commands were introduced or modified: clear ip arp poll statistics , clear ip interface , ip arp poll , ip unnumbered poll , show ip arp poll , and show ip interface unnumbered.