Specifying A Source Address For Icmp Messages - Juniper IGP - CONFIGURATION GUIDE V11.1.X Configuration Manual

ip unreachables

Specifying a Source Address for ICMP Messages

By default, ICMP uses the IP address of the outgoing interface as the source IP
address for the ICMP message. However, you can use the ip icmp update-source
command to instruct ICMP to use an already configured interface or a specified IP
address, as the source address of the ICMP message.
For example, you can specify that ICMP use Fast Ethernet interface 1 in slot 0 as the
source for any messages that it sends:
You must use an already configured interface or an existing IP address when using
the ip icmp update-source command. Also, you cannot specify a multicast address
when using this command.
ip icmp update-source
Use to enable the sending of redirect messages if software is forced to resend a
packet through the same interface on which it was received.
Example
host1(config-if)#ip redirects
Use the no version to disable the sending of redirect messages.
See ip redirects
Use to enable the generation of an ICMP unreachable message when a packet
is received that the router cannot deliver.
Example
host1(config-if)#ip unreachables
Use the no version to disable the function.
See ip unreachables
host1(config)#ip icmp update-source fastEthernet 0/1
Use to define an update source address for all ICMP messages that the E Series
router generates from the specified interface.
Example
host1(config)#ip icmp update-source 192.35.42.1
Use the no version to disable the function.
See ip icmp update-source
Chapter 1: Configuring IP
Internet Control Message Protocol
61