Enabling Hsrp Support For Icmp Redirect Messages; Displaying Hsrp Configurations - Cisco ME 3400 Software Configuration Manual

Displaying HSRP Configurations

Enabling HSRP Support for ICMP Redirect Messages

ICMP (Internet Control Message Protocol) redirect messages are automatically enabled on interfaces
configured with HSRP. This feature filters outgoing ICMP redirect messages through HSRP, in which the next
hop IP address might be changed to an HSRP virtual IP address. ICMP is a network layer Internet protocol
that provides message packets to report errors and other information relevant to IP processing. ICMP
provides diagnostic functions, such as sending and directing error packets to the host.
When the switch is running HSRP, make sure hosts do not discover the interface (or real) MAC addresses
of routers in the HSRP group. If a host is redirected by ICMP to the real MAC address of a router and
that router later fails, packets from the host are lost.
For more information, see the Cisco IOS IP Configuration Guide, Release 12.2.
Displaying HSRP Configurations
From privileged EXEC mode, use this command to display HSRP settings:
show standby [interface-id [group]] [brief] [detail]
You can display HSRP information for the whole switch, for a specific interface, for an HSRP group, or
for an HSRP group on an interface. You can also specify whether to display a concise overview of HSRP
information or detailed HSRP information. The default display is detail. If there are a large number of
HSRP groups, using the show standby command without qualifiers can result in an unwieldy display.
This is a an example of output from the show standby privileged EXEC command, displaying HSRP
information for two standby groups (group 1 and group 100):
Switch# show standby
VLAN1 - Group 1
Local state is Standby, priority 105, may preempt
Hellotime 3 holdtime 10
Next hello sent in 00:00:02.182
Hot standby IP address is 172.20.128.3 configured
Active router is 172.20.128.1 expires in 00:00:09
Standby router is local
Standby virtual mac address is 0000.0c07.ac01
Name is bbb
VLAN1 - Group 100
Local state is Active, priority 105, may preempt
Hellotime 3 holdtime 10
Next hello sent in 00:00:02.262
Hot standby IP address is 172.20.138.51 configured
Active router is local
Standby router is unknown expired
Standby virtual mac address is 0000.0c07.ac64
Name is test
Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
38-12
Chapter 38 Configuring HSRP
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