Re: HSRP active router tells standby to take over when being

Nice post.
As the worker bee pointed out, the reload command triggered graceful
shutdown. Reload is only a command, and its interpretation is really up to a
parser. IOS could draw an ASCII flower upon entering it :)
Usually, it is a good idea to failover test using more real scenarios (test
crash, physical manipulation)
It'd be interesting to trigger resign message some other way, e.g. through a
fast detection mechanism, or a triggered mechanism (like EEM).

Thanks for sharing, Joseph.
Regards,
Pavel
On Wed, Sep 21, 2011 at 6:15 AM, Joseph L. Brunner
<joe_at_affirmedsystems.com>wrote:

> One cool fact I thought I would share with the group - Understanding the
> HSRP
> resign message...
>
> This evening I'm testing various failover scenarios and I have my primary
> (HSRP active) router (.2) the HSRP primary (for .1) on an external segment
> (where 2 ASA's default to the HSRP virtual address (.11 , .10)
>
> I don't use standby tracking on the primary router - it's simply tracking
> its
> local ISP connection default route via an SLA ping of the ISP adjacent
> neighbor on metro-E and track object. I have a backup default route, AD
> 254,
> to the Standby router (.3) on the segment. If the primary router is up, but
> has no valid default route (cause it can't ping the adjacent ISP) it routes
> all traffic to standby router.
>
> So I started my failover testing by rebooting primary router and doing a
> continuous ping of 4.2.2.2. Well, no pings were missed during the reboot!!!
> (I
> expected about 10 missed pings as the standby router became hsrp primary
> and
> took over .1, the default gateway of the ASA's). (if you're sharp you
> caught
> the fact we're obviously natting the first public range to a second public
> range on the standby router to go out a different ISP)
>
> Here is the debug output on the HSRP standby router during the primary's
> reboot (watch for the "resign rcvd" where the primary RESIGNS and allows
> the
> standby to become active MUCH FASTER than the timers)
>
> kcf1515-edge-rtr2#debug standby
> HSRP debugging is on
> kcf1515-edge-rtr2#
> Sep 21 04:08:15.504: HSRP: Gi0/0 Grp 1 Hello in 174.58.91.2 Active pri
> 150
> vIP 174.58.91.1
> Sep 21 04:08:15.824: HSRP: Gi0/0 Grp 1 Hello out 174.58.91.3 Standby pri
> 100
> vIP 174.58.91.1
> Sep 21 04:08:18.824: HSRP: Gi0/0 Grp 1 Hello out 174.58.91.3 Standby pri
> 100
> vIP 174.58.91.1
> Sep 21 04:08:19.352: HSRP: Gi0/0 Grp 1 Hello in 174.58.91.2 Active pri
> 150
> vIP 174.58.91.1
> Sep 21 04:08:21.516: HSRP: Gi0/0 Grp 1 Resign in 174.58.91.2 Active pri
> 150
> vIP 174.58.91.1
> Sep 21 04:08:21.516: HSRP: Gi0/0 Grp 1 Standby: i/Resign rcvd
> (150/174.58.91.2)
> Sep 21 04:08:21.516: HSRP: Gi0/0 Grp 1 Active router is local, was
> 174.58.91.2
> Sep 21 04:08:21.516: HSRP: Gi0/0 Grp 1 Standby router is unknown, was local
> Sep 21 04:08:21.516: HSRP: Gi0/0 Grp 1 Standby -> Active
> Sep 21 04:08:21.516: %HSRP-5-STATECHANGE: GigabitEthernet0/0 Grp 1 state
> Standby -> Active
> Sep 21 04:08:21.516: HSRP: Gi0/0 Grp 1 Redundancy "hsrp-Gi0/0-1" state
> Standby
> -> Active
> Sep 21 04:08:21.516: HSRP: Gi0/0 Redundancy server "hsrp-Gi0/0-1" update,
> Standby -> Active
> Sep 21 04:08:21.516: HSRP: Gi0/0 Redirect adv out, Active, active 1 passive
> 1
> Sep 21 04:08:21.516: HSRP: Gi0/0 Grp 1 Hello out 174.58.91.3 Active pri
> 100
> vIP 174.58.91.1
> Sep 21 04:08:24.516: HSRP: Gi0/0 Grp 1 Hello out 174.58.91.3 Active pri
> 100
> vIP 174.58.91.1
> Sep 21 04:08:24.516: HSRP: Gi0/0 Grp 1 Redundancy group hsrp-Gi0/0-1 state
> Active -> Active
> Sep 21 04:08:27.516: HSRP: Gi0/0 Grp 1 Hello out 174.58.91.3 Active pri
> 100
> vIP 174.58.91.1
> Sep 21 04:08:27.516: HSRP: Gi0/0 Grp 1 Redundancy group hsrp-Gi0/0-1 state
> Active -> Active
> kcf1515-edge-rtr2#
> Sep 21 04:08:30.076: HSRP: Gi0/0 Grp 1 Hello out 174.58.91.3 Active pri
> 100
> vIP 174.58.91.1
> Sep 21 04:08:30.516: HSRP: Gi0/0 Grp 1 Hello out 174.58.91.3 Active pri
> 100
> vIP 174.58.91.1
> kcf1515-edge-rtr2#un all
> All possible debugging has been turned off
>
>
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Received on Thu Sep 22 2011 - 13:40:13 ART