Cisco Catalyst 3750-E

42-12
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-08
Chapter 42 Configuring HSRP
Configuring HSRP
Enabling HSRP Support for ICMP Redirect Messages
ICMP redirect messages are automatically enabled on interfaces configured with HSRP. 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. 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. For more information, see the Cisco IOS IP
Configuration Guide, Release 12.2.
Configuring HSRP Groups and Clustering
When a device is participating in an HSRP standby routing and clustering is enabled, you can use the
same standby group for command switch redundancy and HSRP redundancy. Use the cluster
standby-group HSRP-group-name [routing-redundancy] global configuration command to enable the
same HSRP standby group to be used for command switch and routing redundancy. If you create a cluster
with the same HSRP standby group name without entering the routing-redundancy keyword, HSRP
standby routing is disabled for the group.
This example shows how to bind standby group my_hsrp to the cluster and enable the same HSRP group
t
o be used for command switch redundancy and router redundancy. The command can only be executed
on the cluster command switch. If the standby group name or number does not exist, or if the switch is
a cluster member switch, an error message appears.
Switch# configure terminal
Switch(config)# cluster standby-group my_hsrp routing-redundancy
Switch(config)# end
Troubleshooting HSRP for Mixed Stacks of Catalyst 3750-X, 3750-E and 3750
Switches
If one of the situations in Table 42-2 occurs, this message appears:
%FHRP group not consistent with already configured groups on the switch stack - virtual
MAC reservation failed
Ta b l e 42-2 Troubleshooting HSRP
Situation Action
You configure more than 32 HSRP group instances. Remove HSRP groups so that up to 32 group instances are
co
nfigured.
You configure HSRP for IPv4 and HSRP for IPv6 at the same
tim
e
Configure either HSRP for IPv4 or HSRP for IPv6 on the
switch.
You configure group numbers that are not in valid ranges of
2
56.
Configure group numbers in a valid range.