[f-nsp] BGP best path on a XMR

[Erich Hohermuth]

Hi

> "redistribution connected" in the OSPF fixed that.

Be aware, that this solution has some drawbacks in scalability. Also it
sets your loopback ip as E2 OSPF route. An other solution is to set the
bgp feature next-hop-self for the iBGP Session. 

If you really like to have the upstream transfer network in your routing
table it is better to control the routes with a route-map on the
redistribute command. 

Regards
	Erich


> 
> On 7/23/07, Mike Leber <mleber at he.net> wrote:
> >
> > Typical reason for the below would be the next hop isn't in the routing
> > table of that router.
> >
> > Do the two routers share their connected and static routes via an IGP,
> > such as OSPF?
> >
> > If not, setting that up would fix it.
> >
> > On Mon, 23 Jul 2007, Morten Isaksen wrote:
> >
> > > Hi!
> > >
> > > I have two XMR's that that each has a BGP connection to an upstream
> > > provider and i IBGP link between them. I am trying to force traffic to
> > > some prefixes via one of the upstreams and have made a route map that
> > > set the local pref i bit higher for these prefixes, but the XMR seems
> > > to ignore this. Or maybe I have misunderstood the best path algorithm.
> > >
> > > SSH at BGP-2>sh ip bgp route detail 194.255.106.0
> > > Number of BGP Routes matching display condition : 2
> > > Status A:AGGREGATE B:BEST b:NOT-INSTALLED-BEST C:CONFED_EBGP D:DAMPED
> > >        E:EBGP H:HISTORY I:IBGP L:LOCAL M:MULTIPATH m:NOT-INSTALLED-MULTIPATH
> > >        S:SUPPRESSED F:FILTERED s:STALE
> > > 1       Prefix: 194.255.0.0/16,  Status: BE,  Age: 2d22h10m20s
> > >          NEXT_HOP: 217.74.212.65,  Learned from Peer: 217.74.212.65 (29542)
> > >           LOCAL_PREF: 100,  MED: none,  ORIGIN: igp,  Weight: 0
> > >            AS_PATH: 29542 9167 3308
> > >             COMMUNITIES: 9167:50203 29542:301 29542:321 43027:310
> > >             Adj_RIB_out count: 1,  Admin distance 20
> > > 2       Prefix: 194.255.0.0/16,  Status: I,  Age: 0h15m39s
> > >          NEXT_HOP: 194.19.218.157,  Learned from Peer: 77.75.166.253 (43027)
> > >           LOCAL_PREF: 110,  MED: none,  ORIGIN: igp,  Weight: 0
> > >            AS_PATH: 3308
> > >             COMMUNITIES: 43027:300
> > >        Last update to IP routing table: 2d22h10m20s, 1 path(s) installed:
> > >        Route is advertised to 1 peers:
> > >         77.75.166.253(43027)
> > >
> > >
> > > In my world route 2 should be preferred since it has the highest local
> > > pref, but the XMR prefers route 1.
> > >
> > > Can somebody explain why? And how do I make it choose route 2 as the best path?

-- 
* Erich Hohermuth IP Engineer - SolNet (AS 9044) PGPKEY-46A08FCB *
   * phone: +41 32 517 6220 / sip:9044*463 at inoc-dba.pch.net *