[j-nsp] Troubleshooting BGP

[Stefan Fouant]

On Wed, Oct 7, 2009 at 10:15 PM, Jason Lixfeld <jason at lixfeld.ca> wrote:

> If I'm reading this correctly, the router is preferring the OSPF route over
> the BGP route, which makes sense because OSPF has a lower administrative
> distance (is that a Juniper term too, or just a Cisco term?) than iBGP.
>  This shouldn't prevent the route from being announced to eBGP peers (at
> least it doesn't in Cisco land, but maybe there are differences in how J and
> C work in this regard which I'm missing) should it?
>
> user at router> show route 69.57.14.0 detail
>
> inet.0: 296972 destinations, 664182 routes (296971 active, 0 holddown, 1
> hidden)
> 69.57.14.0/24 (2 entries, 1 announced)
>        *OSPF   Preference: 150
>                Next hop type: Router, Next hop index: 530
>                Next-hop reference count: 1262
>                Next hop: 72.15.49.21 via ge-2/0/1.0, selected
>                State: <Active Int Ext>
>                Local AS: 21949
>                Age: 1:11:22    Metric: 2020    Tag: 0
>                Task: OSPFv2
>                Announcement bits (2): 0-KRT 5-Resolve tree 1
>                AS path: I
>         BGP    Preference: 170/-791
>                Next hop type: Indirect
>                Next-hop reference count: 1
>                Source: 72.15.48.2
>                Next hop type: Router, Next hop index: 530
>                Next hop: 72.15.49.21 via ge-2/0/1.0, selected
>                Protocol next hop: 206.223.182.67
>                Indirect next hop: 155101d4 1048579
>                State: <Int Ext>
>                Inactive reason: Route Preference
>                Local AS: 21949 Peer AS: 21949
>                Age: 1:11:27    Metric: 0       Metric2: 2020
>                Task: BGP_21949.72.15.48.2+179
>                AS path: I (Originator) Cluster list:  66.207.194.20
>                AS path:  Originator ID: 72.15.48.6
>                Communities: 21949:70 21949:790
>                Localpref: 790
>                Router ID: 66.207.194.20
>

Yep, the OSPF route is preferred, you can see that in your display by
looking at the * symbol next, which indicates which route is active.  Also
you can see that the BGP route has an "Inactive reason: Route Preference",
which makes sense in this case because as you indicate the default
preference value for OSPF externals is lower than BGP routes.  By default,
BGP will only advertise active BGP routes.  You'll need to either put in a
policy to redistribute the OSPF route to BGP, or use the advertise-inactive
command to advertise the inactive BGP route.

-- 
Stefan Fouant