Allied Telesis 86253-07 manual Enable and Disable ICMP Messages, Commands, Disable Ip Icmpreply

28 SHOW IGMPSNOOPING ROUTERADDRESS Patch Release Note

Enable and Disable ICMP Messages

The Internet Control Message Protocol (ICMP) allows routers to send error and control messages to other routers or hosts. It provides the communication between IP software on one system and IP software on another.

This enhancement allows the switch to enable or disable some ICMP messages when directed by the network manager.

The ICMP messages that are able to be enabled or disabled are:

■Network unreachable (RFC792 Type 3 Code 0)

■Host unreachable (RFC792 Type 3 Code 1)

■ICMP redirect messages (RFC792 Type 5 Code 0, 1, 2, 3)

Network Unreachable

This message indicates that the switch does not know how to reach the destination network.

Host Unreachable

This message indicates that the switch does not know how to reach the host.

ICMP Redirect

This message is sent to a local host to tell it that its target is located on the same LAN (no routing is required) or when it detects a host using a non-optimal route (usually because a link has failed or changed its status) on a directly connected router to advise of a better route to a particular destination.

For more information on ICMP, see the IP Chapter in your switch’s Software

Reference manual.

Commands

This enhancement introduces three new commands:

■DISABLE IP ICMPREPLY

■ENABLE IP ICMPREPLY

■SHOW IP ICMPREPLY

DISABLE IP ICMPREPLY

Syntax DISABLE IP ICMPREPLY[={ALLNETUNREACHHOSTUNREACHREDIRECT}]

Description This command disables ICMP reply messages.

Patch 86253-07 for Software Release 2.5.3 C613-10382-00 REV E