[c-nsp] ibgp prefix advertisement

[Shakeel Ahmad]

iBGP should be fully meshed in between iBGP peers. otherwise CUSTOACESS will
not advertise the routes which it learned from its eBGP peer and if you want
to use this same setup...


CUSTOACESS(41.220.15.253)--ibgp--CUSTODIST(41.220.15.250)--ibgp--IXROUTER(
41.220.15.252)


Route reflector may be another option...but usual in IXP simpe iBGP mesh is
used.


Shakeel


On 8/8/06, Dave Temkin <dave at ordinaryworld.com> wrote:
>
> OK, I haven't had my coffee yet.  Stupid statement in last email.
>
> Disabling sync will get them in the local table of CUSTODIST, but not into
> IXROUTER.  You need to either make CUSTODIST a route reflector or mesh
> CUSTOACCESS to IXROUTER.
>
> -Dave
>
> On Tue, 8 Aug 2006, Dave Temkin wrote:
>
> > You need to disable synchronization on CUSTOACCESS (no sync in router
> > bgp).
> >
> > Rules of iBGP say every speaker must be meshed.  In your setup, they
> don't
> > really *need* to be, and to overcome this you must disable sync.
> > The correct method, however, would be to enable a session directly
> between
> > CUSTOACCESS and IXROUTER.
> >
> >
> > -Dave
> >
> > On Tue, 8 Aug 2006, Mikisa Richard wrote:
> >
> > > Hi all,
> > >
> > > Scenario
> > >
> > > AS29032--ebgp--CUSTOACESS(41.220.15.253)--ibgp--CUSTODIST(
> 41.220.15.250)--ibgp--IXROUTER(41.220.15.252)
> > >
> > >
> > > Problem is that CUSTODIST receives prefixes from CUSTOACESS but does
> not
> > > advertise them to IXROUTER.
> > >
> > > from CUSTODIST ....
> > >
> > > distro#show ip bgp su
> > > BGP router identifier 41.220.15.250, local AS number 28941
> > > BGP table version is 231, main routing table version 231
> > > 29 network entries and 30 paths using 3893 bytes of memory
> > > 8 BGP path attribute entries using 480 bytes of memory
> > > 5 BGP AS-PATH entries using 120 bytes of memory
> > > 0 BGP route-map cache entries using 0 bytes of memory
> > > 0 BGP filter-list cache entries using 0 bytes of memory
> > > BGP activity 78/633 prefixes, 105/75 paths, scan interval 15 secs
> > >
> > > Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down
> > > State/PfxRcd
> > > 41.220.15.252   4 28941     388     370      231    0    0
> 00:25:14       25
> > > 41.220.15.253   4 28941     953     949      231    0    0
> 15:46:40        5
> > >
> > >
> > > distro#show ip bgp ne 41.220.15.253 ro
> > > BGP table version is 231, local router ID is 41.220.15.250
> > > Status codes: s suppressed, d damped, h history, * valid, > best, i -
> > > internal
> > > Origin codes: i - IGP, e - EGP, ? - incomplete
> > >
> > >     Network          Next Hop            Metric LocPrf Weight Path
> > > *>i0.0.0.0          41.220.15.253                 100      0 29032 i
> > > *>i41.220.0.0/20    41.220.15.253            0    100      0 29032 i
> > > * i41.220.14.0/23   41.220.15.253            0    100      0 i
> > > *>i217.212.230.0/23 41.220.15.253                 100      0 29032 i
> > > *>i217.212.242.0/23 41.220.15.253                 100      0 29032 i
> > >
> > > Total number of prefixes 5
> > >
> > > distro#show ip bgp 217.212.242.0
> > > BGP routing table entry for 217.212.242.0/23, version 206
> > > Paths: (1 available, best #1, table Default-IP-Routing-Table)
> > >    Not advertised to any peer
> > >    29032, (received & used)
> > >      41.220.15.253 (metric 11) from 41.220.15.253 (41.220.15.253)
> > >        Origin IGP, localpref 100, valid, internal, best
> > >
> > >
> > > distro#show ip bgp ne 41.220.15.252 ad
> > > distro#
> > >
> > >
> > > Any ideas on why CUSTODIST is not advertising?
> > >
> > >
> >
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