System information

Troubleshooting TCP/IP
Book Title
7-136
HSRP is not configured
or is misconfigured
Step 1 Try to ping the hot standby IP address. If the ping is unsuccessful,
proceed to Step 2. If the ping is successful, proceed to Step 4.
Step 2 Use the show standby privileged exec command to see information about
the HSRP configuration. If the command does not return any output,
HSRP is not configured on the router interface.
Step 3 If HSRP is not configured, configure it on the routers that you want to
belong to the hot standby group.
For example, to configure a router as the active hot standby router with
hot standby address 192.192.192.3, enter the following commands:
C4500(config)#interface e0
C4500(config-if)#standby ip 192.192.192.3
C4500(config-if)#standby priority 110
C4500(config-if)#standby preempt
The standby priority interface configuration command sets the router’s
HSRP priority; the default priority is 100.
To configure a router as the backup hot standby router, enter the following
commands:
C4500(config)#interface e0
C4500(config-if)#standby ip 192.192.192.3
Step 4
If the backup hot standby router is misconfigured and the active router
fails, the backup router might not go active.
One potential misconfiguration is a missing hot standby address in the
backup router. You can successfully configure a router as a hot standby
router simply by entering the following commands:
C4500(config)#interface e0
C4500(config-if)#standby ip
That is, you do not have to include the hot standby IP address in the
standby ip command. As long as one hot standby router has the hot
standby IP address in its configuration, every other hot standby router will
learn the address from that router. However, if only one router has the hot
standby address configured, and that router fails, other hot standby
routers will not know the hot standby address and HSRP will not work.
Be sure that at least two hot standby routers have the hot standby address
in their configuration.
No routes in active
hot standby router
If HSRP appears to be configured correctly, but connectivity fails, make sure that
your other routing protocols are working correctly. If your other routing protocols
are not advertising routes correctly, hot standby routers will have incomplete or
empty routing tables, and traffic will not be forwarded correctly.
Follow the troubleshooting procedures outlined in this chapter to ensure that your
other routing protocols work correctly.
Possible Problem Solution