[j-nsp] PE-CE BGP announcements

[Michael Still]

Is this just a case of BGP loop prevention working as expected? If I
understand correctly you are learning it from AS12345 but also wish to
announce it to a diff neighbor in AS12345? If so then try 'as-override'
option.


On Thu, Mar 7, 2019 at 2:06 PM Jason Lixfeld <jason-jnsp at lixfeld.ca> wrote:

> Hello,
>
> I’m trying to work through solving why a BGP prefix 126.126.126.0/24
> announced to pe2 in vrf foo isn’t announced to EBGP neighbour 10.108.35.254
> on pe1 that is also in vrf foo.
>
> jlixfeld at pe1# run show route protocol bgp table foo.inet.0
> 126.126.126.0/24
>
> foo.inet.0: 41 destinations, 51 routes (35 active, 0 holddown, 9 hidden)
> + = Active Route, - = Last Active, * = Both
>
> 126.126.126.0/24   *[BGP/170] 03:18:28, MED 0, localpref 990, from
> 10.15.48.253
>                       AS path: 12345 I, validation-state: unverified
>                     > to 10.15.51.248 via xe-0/1/5.0, Push 91
>                       to 10.15.49.83 via xe-0/1/0.0, Push 91, Push 18(top)
>                     [BGP/170] 03:18:28, MED 0, localpref 990, from
> 10.15.48.254
>                       AS path: 12345 I, validation-state: unverified
>                     > to 10.15.51.248 via xe-0/1/5.0, Push 91
>                       to 10.15.49.83 via xe-0/1/0.0, Push 91, Push 18(top)
>
> [edit]
> jlixfeld at pe1#
>
> 126.126.126.0/24 is received from as12345 on pe2.  pe2 announces the
> prefix to RRs 10.15.48.253 and 10.15.48.254, and the RRs announce the
> prefix to pe1.  From here, I’m trying to announce it to EBGP neighbour
> 10.108.35.254, which I can’t seem to make work:
>
> jlixfeld at pe1# run show route advertising-protocol bgp 10.108.35.254
>
> foo.inet.0: 41 destinations, 51 routes (35 active, 0 holddown, 9 hidden)
>   Prefix                  Nexthop              MED     Lclpref    AS path
> * 10.137.128.0/21         Self                                    I
> * 10.137.136.0/21         Self                                    I
> * 10.137.144.0/21         Self                                    I
> * 10.137.152.0/21         Self                                    I
> * 10.207.192.0/19         Self                                    I
> * 10.15.48.0/22           Self                                    I
> * 10.15.52.0/22           Self                                    I
> * 10.15.56.0/22           Self                                    I
> * 10.15.60.0/22           Self                                    I
> * 10.98.192.0/20          Self                                    I
> * 10.9.192.0/19           Self                                    I
> * 10.45.192.0/20          Self                                    I
> * 10.192.44.0/22          Self                                    I
> * 10.59.160.0/20          Self                                    I
> * 10.249.160.0/22         Self                                    I
> * 10.68.120.0/21          Self                                    I
> * 10.167.152.0/21         Self                                    I
> * 10.175.212.0/22         Self                                    I
> * 10.223.160.0/19         Self                                    I
> * 10.253.136.0/21         Self                                    I
>
> [edit]
> jlixfeld at pe1#
>
> (FWIW, the prefixes that are being announced are anchored on pe1 as static
> routes)
>
> My understanding is that since this is a BGP prefix, it’s default export
> policy is to advertise all active BGP routes to all BGP speakers.  But, to
> try and work through whether it was an export policy issue anyway, I
> deactivated the export policy on the session to 10.108.35.254, which was
> ineffective.
>
> Maybe there are additional default behaviours that are different than what
> I’m more familiar with in IOS/XR?
>
> Maybe it is actually a policy issue, and I’m just not aware of what’s
> necessary for the prefix get announced.  I was hoping that there was an
> equivalent to show route receive-protocol bgp <neighbor> hidden table <..>
> detail that would show why a prefix may not be getting announced to an EBGP
> neighbor.  IE: this command would show the reasons why a received route is
> hidden, ie: "Hidden reason: rejected by import policy”.
>
> Would someone be able to point me in the direction of where I might need
> to look to clear up what I’m missing?
>
> Thanks!
>
>
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp
>


-- 
[stillwaxin at gmail.com ~]$ cat .signature
cat: .signature: No such file or directory
[stillwaxin at gmail.com ~]$