40 Patch Release Note
Patch 86222-27 for Software Release 2.2.2
C613-10319-00 REV Z
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[={ALL|NETUNREACH|HOSTUNREACH|REDIRECT}]
Description This command disables ICMP reply messages.