BGP- Prefix Info

mahesh_kv3 · ‎09-07-2008

Network Next Hop Metric LocPrf Weight Path

*> 20.20.20.0/30 0.0.0.0 0 32768 ?

This is a prefix entry in the global bgp table what it actually infers.

guruprasadr · ‎09-07-2008

HI Mahesh, [Pls Rate if HELPS]

? - incomplete, * valid, > best

The above Network Prefix is already a VALID Path in the Network.

The outbound traffic from the Router will take the default BGP next-hop for the prefix.

Hope I am informative.

Pls RATE if HELPS

Best Regards,

Guru Prasad R

mahesh_kv3 · ‎09-07-2008

Thanx for that

So what you mean if the BGP is taking the path tru which the advertisement is coming will show the NEXT_HOP 0.0.0.0 is it???

so if there is multiple paths to the destination then only it wll show the exact NEXT_HOP specifically .

wheather there is multiple best routes to a single destination???

Please clear this as well????

Giuseppe Larosa · ‎09-07-2008

Hello Mahesh, this advertisement has been locally generated on the router you can see this from:

a) 0.0.0.0 next-hop means the router itself

b) weight 32768 that is the default value for locally generated prefixes.

By the origin ?=incomplete you can understand that this prefix has been imported as the result of a redistribution into BGP.

Do a sh ip route 20.20.20.0 to see the origin of this route, the output will say redistributed into BGP and advertised by BGP (if advertised to any peer)

It can be the result of redistribute connected for example.

When there are multiple paths to a destination you will see one row for each but the prefix is shown in the first row only and all the other rows will list their own BGP next hop, weight ,... , AS path, origin code.

The best path is marked with *> symbols.

Hope to help

Giuseppe