Users Guide

Layer 3 Routing Commands 1512
User Guidelines
IP unnumbered interfaces are supported in the default VRF only.
The interface should be configured as able to borrow an IP address, i.e. a
routing interface with no IP address.
Normally, the static ARP entry is only installed if the IP address matches one
of the local subnets. In case of unnumbered interfaces, static ARP entries
created for the unnumbered-peer do not match any of the local subnets. By
specifying the interface explicitly in the static ARP command, static ARP
entries for unnumbered-peers can be installed in the ARP table.
Command History
Introduced in version 6.2.0.1 firmware.
Example
console(config-if-vlan1)#ip unnumbered gratuitous-arp accept
ip unreachables
Use the ip unreachables command to enable the generation of ICMP
Destination Unreachable messages. Use the no form of this command to
prevent the generation of ICMP Destination Unreachable messages.
Syntax
ip unreachables
no ip unreachables
Default Configuration
ICMP Destination Unreachable messages are enabled.
Command Mode
Interface Configuration (VLAN) mode
User Guidelines
There are no user guidelines for this command.