[c-nsp] BGP Advertised Prefixes

[Ahmed Hilmy]

Yes, that is right. outbound prefixes are based on prefix-list filter that
has been configured.
Same prefix-list has been set on other UP Links and BGP session works fine,
really strange.

I have set max-prefix at maximum value because i am receiving full BGP
table.



On Tue, Apr 9, 2013 at 11:38 PM, Jason Lixfeld <jason at lixfeld.ca> wrote:

> max-prefix isn't an outbound mechanism, it's in inbound one.  Setting max
> prefix on a neighbor won't prevent it from announcing a zillion prefixes to
> that neighbor, it will only prevent that session from receiving a zillion
> prefixes from the neighbor where the max prefix setting is configured.
>
> That detail output for Prefixes advertised has nothing to do with the
> total number of prefixes advertised to that neighbour at the time the
> command was run.  I think it just tells you how many prefixes it's
> announced throughout the lifetime of the session.   I think that number
> will increment anytime a prefix is added for whatever reason (downstream
> link flap, static route removal, whatever).
>
> On 2013-04-09, at 4:27 PM, Ahmed Hilmy <hilmy.aa at gmail.com> wrote:
>
> >  Hello Jason,
> > thanks for your reply, i know that it clear but why this is happened,
> the filter has been set on both side identical.
> > Kindly, find below log,
> > # sh bgp neighbor x.x.x.x detail | i Prefix advertised
> >
> >   Prefix advertised 2735, suppressed 0, withdrawn 1855, maximum limit
> 524288
> >
> > #sh bgp neighbor  x.x.x.x advertised-routes
> >
> > i count the number of advertised prefixes are only 215
> >
> > Neighbor  x.x.x.x is my UP Link, Prefix list filter has been configured
> to allow a specific prefixes to be announced.
> >
> > What do you think ?
> >
> >
> >
> > On Tue, Apr 9, 2013 at 11:21 PM, Jason Lixfeld <jason at lixfeld.ca> wrote:
> > The message is pretty clear.  x.x.x.x is announcing more prefixes than
> what your max prefix setting is configured for.  Either the uplink side is
> misconfigured or your max prefix setting is too small.
> >
> > On 2013-04-09, at 4:13 PM, Ahmed Hilmy <hilmy.aa at gmail.com> wrote:
> >
> > > Dear Friends,
> > >
> > > Recently i have faced a strange issue, BGP session with my UP Links
> goes
> > > down due this log at UP Link side:
> > > ---------------------------------------------------
> > >
> > > RP/0/RSP0/CPU0:Apr  8 13:10:54.818 : bgp[1044]:
> %ROUTING-BGP-4-MAXPFXEXCEED
> > > : No. of IPv4 Unicast prefixes received from x.x.x.x: 401 exceed limit
> 400
> > >
> > > RP/0/RSP0/CPU0:Apr  8 13:10:54.818 : bgp[1044]:
> %ROUTING-BGP-5-ADJCHANGE :
> > > neighbor x.x.x.x Down - Peer exceeding maximum prefix limit (CEASE
> > > notification sent - maximum n           umber of prefixes reached)
> (VRF:
> > > default)
> > >
> > >
> > > -------------------------------------------------------------
> > >
> > > # sh bgp neighbor x.x.x.x detail | i Prefix advertised
> > >
> > >  Prefix advertised 2735, suppressed 0, withdrawn 1855, maximum limit
> 524288
> > > #sh bgp neighbor  x.x.x.x advertised-routes
> > >
> > > i count the number of advertised prefixes are only 215
> > >
> > > So what Prefix advertised 2735 does it mean ?
> > > Why i faced this issue with my UP Links , it happened sometime , if i
> have
> > > configured BGP filter in wrong way so i have to face this
> > > issue continuously.
> > >
> > > Any suggest plan to check ?
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> >
> >
>
>