Re: BGP DOUBT

History means that the route was there, but now it is gone.
What for ? To keep the number of times it has "come and gone"
(flap count) you need a place to keep that info.

Stale, on the other hand, is a NSF *still usable* route received
from a neighbour that is undergoing a graceful restart (sup
switchover).

You have to be NSF aware for having these, and your neighbour has to
be NSF capable.

Kambiz, can you please show us some piece of evidence to stale routes
not being CEF valid ?

-Carlos

Kambiz Agahian @ 18/06/2010 16:40 -0300 dixit:
> Very briefly in BGP-4 the stale flag (for a stale route) is used to
> indicate the routes that are no longer valid from the CEF point of view.
> For instance in NSF once the routing protocol finishes the convergence
> process, CEF updates the FIB table and takes stale route entries off.
>
> The History flag however is used in the context of dampening - if that's
> what you mean.
>
> r0#show ip bgp 10.0.0.0/8 longer-prefixes
> local router ID is 10.0.0.1
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal,
> r RIB-failure, S Stale
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
>
> HTH
>
>
> --------------------------
> Kambiz Agahian
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>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> HEMANTH RAJ
> Sent: Friday, June 18, 2010 12:02 PM
> To: Cisco certification
> Subject: BGP DOUBT
>
> Wat is the difference between stale and history flag???
>

-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
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