HSRP

[ney25]

hi netpro,

anyone know why the HSRP will fail over suddenly ? that's no any device fail or uplink broken..

685390: Jan 8 15:40:37.735 Singapo: %STANDBY-6-STATECHANGE: Vlan270 Group 70 state Active -> Speak

685391: Jan 8 15:40:38.083 Singapo: %STANDBY-6-STATECHANGE: Vlan313 Group 113 state Active -> Speak

685392: Jan 8 15:40:38.127 Singapo: %STANDBY-6-STATECHANGE: Vlan314 Group 114 state Active -> Speak

634567: Jan 8 15:40:37.763 Singapo: %STANDBY-6-STATECHANGE: Vlan531 Group 231 state Active -> Speak

685387: Jan 8 15:40:36.547 Singapo: %STANDBY-6-STATECHANGE: Vlan268 Group 68 state Active -> Speak

685388: Jan 8 15:40:36.899 Singapo: %STANDBY-6-STATECHANGE: Vlan274 Group 74 state Active -> Speak

685389: Jan 8 15:40:37.191 Singapo: %STANDBY-6-STATECHANGE: Vlan276 Group 76 state Active -> Speak

your reply will be highly appreciated.

regards,

Jack

[ankbhasi]

Hi Jack,

Are you sure that the vlan interface were never down on active router? Can you check the logs and confirm? If 3 hello packet are missed continuously from active to standby it will failover.

This can be due to network congestion that 3 packets got dropped or may be your something happen to the hardware that 3 packets got dropped. Can you recheck the logs and confirm? Which platform is this?

Regards,

Ankur

[s.arunkumar]

To add to above try increasing ur hsrp hello and hold time..

[ney25]

Hi bro,

yes, i am confirmed my hardware is not faulty.

but, i wonder how come few vlans can fail over at the same time ?

i have implemented hello and hold time as well.

regards,

jack

[ankbhasi]

Hi Ney,

I will like to know which platform is this? One of the reason all vlans can flap is if lets say there is only a trunk link between this switch and some layer 2 switch downlink and no other machines are connected to these vlans on layer 3 switch and if trunk port flaps all layer 3 virtual interfaces may flap.

I will not recommend to increase the HSRP timers untill and unless required and will like to know what is the root cause of this issue. So did you get a chance to look at the logs?

Regards,

Ankur

[ney25]

Hi Ankur,

nothing much on the logs. but this information was captured from Core-switch <6509>.

besides, any idea why few vlans could failed over at the same time ?

regards,

Jack

[ankbhasi]

Hi Jack,

Did you see interface vlans went down and come up in your logs? No errors related to line cards? I belive if there is a congestion or communication failure for short while between your msfc and sups this may cause an issue but because you do not see anything specific in logs I doubts that is an issue.

Not sure though why HSRP moves to standby router but if you see vlan interface flapped that was a potential cause of HSRP moves to standby router but why vlan interface flapped can be only determined if we see something wrong in logs which as you mentioned does not have anything.

Regards,

Ankur

Regards,

Ankur

[ney25]

Hi Ankur,

would it be STP problem ? because, i noticed some of the vlan root bridge is not in the core-switch.

your reply will be highly appreciated.

regards,

Jack

[ankbhasi]

Hi Jack,

Could be, it lot depends upon your topology. STP and HSRP can be closly related depending upon topology and design.

Regards,

Ankur