HSRP Taking time to failover

[ankitohc]

Hi Team,

I just want to know its just a normal behavaiour - Does it 10 seconds to become active?

[MHM Cisco World]

Friend check this link 

https://andrewroderos.com/optimizing-hsrp-timers/

See what cisco TAC suggests.

MHM

[Joseph W. Doherty]

"See what cisco TAC suggests."

It appears they suggest what Cisco notes in the document I referenced earlier.

That said, a nicely written article.  I too concur, in my experience with BFD (FHRP and IGP), using values below 250 ms, doesn't always work out too well.  I.e. it can be difficult to meet the 50 ms failure detection SONET standard.  (This [12/29/2007] NetworkWorld Jeff Doyle article, touches on this issue, even with BFD.)

[MHM Cisco World]

I know, in real network the BFD interval must config carefully otherwise it can be problem not solution. 
but BFD is different than HSRP hello in that it not run in CPU, it run in Interface, which make it not effect by busy CPU. 
anyway I think @ankitohc get full view of what happened here. 
hope both help him as we could 
Have a nice weekend friend 
MHM

[Joseph W. Doherty]

"but BFD is different than HSRP hello in that it not run in CPU, it run in Interface, which make it not effect by busy CPU. "

"Different", yes and no.

". . . it not run in CPU . . ." Ah, not quite.  It may, and likely does, use the CPU, but one of its goals is "low-overhead", i.e. it shouldn't tax the CPU nearly as much as other older liveness detection protocols do.  By its RFC 5880, it's desired that as much as possible might be done at the data plane, but implementations will depend on the feature of the underlying hardware.

In OS terms, it might be somewhat analogous to considering something like HSRP a "process" and BFD a "thread".  Or, perhaps in Cisco router terms, somewhat analogous, HSRP is "process switched" while BFD is "fast (interrupt) switched".

[Ruben Cocheno]

@ankitohc 

Consider using HSRP BFD which increases convergence, but note that virtual resources in Lab context might not give you realistic values as in real hardware.

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipapp_fhrp/configuration/15-mt/fhp-15-mt-book/fhp-hsrp-bfd.html