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VRRP Log Entry

Trevor Commulynx
Regular Advisor

VRRP Log Entry

Hi Guys,

Got a bit of a funny one. I have VVRP setup between 2x 5406zl switches. CORE-A is the Master and CORE-B is the Backup. 3x Vlans have Virtual routers configured. the servers etc are VID2. This is the network having the issue. every 35 minutes or so, a log entry appears in CORE-A's log stating the following:

W 07/06/09 16:12:11 00793 vrrp: Vrid 2 ,Vid 2 IP addr is duplicated on n/w(4)
W 07/06/09 16:02:10 00793 vrrp: Vrid 2 ,Vid 2 IP addr is duplicated on n/w(1)

this started happening after we had an extended power outage over the weekend. I dont know whether this is coincidence or what, but to me it seems like somthing else on the network has the same address as the gateway. Also, I have checked the VRRP logs on the backup router and it hasnt tried to take over as master.

this lasts for about 2-5 mintues then all back to normal. any ideas?

Trev.
7 REPLIES
Pieter 't Hart
Honored Contributor

Re: VRRP Log Entry

looks to mee that a config change was not saved.

what's connected to n/w(1) and n/w(4) ?
what are the details op the ip and vrrp config?

Trevor Commulynx
Regular Advisor

Re: VRRP Log Entry

thanks for the reply. the config was saved, hasnt changed for over a month. I really need to know what the error means? Also, this is MSTP config using VRRP.

also, should have mentioned this happens every 1hr to the second and lasts for 17 minutes exactly. also, failover happens but the backup router doesnt adopt the master (owner) IP.

I will upload the configs, just need to modify some details.

Trev.
Trevor Commulynx
Regular Advisor

Re: VRRP Log Entry

config attached for Switch.
Pieter 't Hart
Honored Contributor

Re: VRRP Log Entry

this config looks allright to me.
what's the backup-swithches config?

when using MSTP, all switches in your network must use the same mstp config.
- check all switches
- check for rogue switches (not configured by IT department) by looking at the mac-adress-table of ports.
- you may temporarily disable vrrp on the backup router(s) and check if messages keep coming
Trevor Commulynx
Regular Advisor

Re: VRRP Log Entry

Does anyone actually know what that log entry means? "on n/w(4)" etc.? I have seen log entries that refer to (7) and (9).

Cheers.
Trevor Commulynx
Regular Advisor

Re: VRRP Log Entry

Hey Ya'll,

Thanks for the replies. Solved the issue. the log entry actually means that there is a duplicated IP address on the network. Someone with linux skills but network skills thought they needed to add a secondary IP address to a second nic on the Redhat server that would only get access when a cron job ran every 1hr and ran for 15 minutes. the ARP tables throughout the network took about 5 to refresh.

What a pain to locate!

Trev.
Trevor Commulynx
Regular Advisor

Re: VRRP Log Entry

see above reply