HSRP Troubleshooting

From: GNS3 Vault (1) Thanks to Rene Molenaar for taking the time to post these practice labs on his site.

• Router New York, New Jersey and LA are configured for HSRP so router Host has a virtual gateway IP address.
• Fix HSRP so router NewYork, NewJersey and LA are in the same HSRP Group and form a single virtual gateway.
• Each HSRP router should be able to become the active router and forward IP packets from the host to the ISP.

Extras:

• Host needs to ping ISP
• New York should be the Active
• New Jersey should be the Standby
• Verify LA becomes Active should New York and New Jersey fail

Topology created by Rene Molenaar from GNS3 Vault (1)

A solution (just my solution):

Verity HSRP for New York, New Jersey and LA:

New York:

New Jersey

LA

We can see that:

• New Jersey and LA are in Group 1 while New York is in Group 11.
• Virtual IP for all three is the same (192.168.1.254)
• New Jersey does not have Preemption enabled
• New York has Authentication text “vault” but in Group 11; New Jersey has authentication text “vualt" and LA does not have any authentication
• New York has priority 180; New Jersey has priority 200; LA has priority 190.

Solve:

• Change New York to Group 1; enable authentication text “vault” for Group 1 along with preemption
• Enable preemption for New Jersey
• Change New Jersey authentication text to “vault”; on LA, enable authentication text “vault” //since authentication is enabled on two of the three I’m assuming it should be enabled on all three
• Make New York the Active (change priority to 200); make New Jersey the secondary (change priority to 150); make LA the last resort (change priority to 100)

The following should fix most of the problems… Lets Go!

Change New York to Group 1, add authentication & preempt:

NewYork(config)#inter fa0/0
NewYork(config-if)#no standby 11
NewYork(config-if)#standby 1
*Mar 1 00:41:12.795: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 11 state Active –> Disabled
NewYork(config-if)#standby 1 ip 192.168.1.254
*Mar 1 00:41:34.831: %HSRP-4-BADAUTH: Bad authentication from 192.168.1.2, group 1, remote state Active
NewYork(config-if)#
NewYork(config-if)#standby 1 authentication text vault
NewYork(config)#inter fa0/0
NewYork(config-if)#standby 1 preempt

Enable preemption for New Jersey & change authentication text to “vault”

NewJersey(config)#inter fa0/0
NewJersey(config-if)#standby 1 preempt
NewJersey(config-if)#standby 1 authentication text vault

Enable authentication text “vault” on LA:

LA(config)#inter fa0/0
LA(config-if)#standby 1 authentication text vault
LA(config-if)#

Make New York the Active (change priority to 200)

NewYork(config-if)#standby 1 priority 200

Make New Jersey the secondary (change priority to 150)

NewJersey(config-if)#standby 1 priority 150

Make LA the last resort (change priority to 100)

LA(config-if)#standby 1 priority 100

Now, verfify:

New York

New Jersey

LA

Looks good; from the above we can see New Jersey will take over if New York fails. We need to verify that LA will take over if both New York and New Jersey fail and that Host can ping ISP.

Host can ping ISP:

Ping fails. Show ip route tells us that Host has a default-gateway of 192.168.11.254 – gateway should be the HSRP Virtual IP 192.168.1.254. Change default-gateway on Host:

Host#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Host(config)#ip default-gateway 192.168.1.254

Verify and retry ping:

We lost one 1 packet to ARP but we’re good! Last item, verify LA becomes active if New York / Jersey fail. For this I’ll shut their fa0/0 interfaces down and then do a show standby on LA:

NewYork(config)#inter fa0/0
NewYork(config-if)#shut

For New Jersey we see the state change to Active before we shut down its inter f0/0:

Verify LA is now active:

And we are done! Cheers!
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1) http://gns3vault.com/Troubleshooting/hsrp-troubleshooting.html