03-28-2008 08:05 AM - edited 03-03-2019 09:19 PM
Hi All
I have three sites (A,B,C) connected through MPLS-VPN using protocol BGP with AD 20(EBGP).Site A is our central site and we have secondary link (VSAT),Site A to B and A to C. Now I want to use same protocol for secondary link and traffic should be move through MPLS-VPN while both the link up.
for mpls link config like blow
router bgp 63590
network x.x.x.x mask x.x.x.x
network x.x.x.x mask x.x.x.x
neighbour x.x.x.x remote-as 9829
all the sites (A,B,C) having bgp AS 63590
How to configure secondary link (VSAT) using same protocol ?
03-28-2008 12:00 PM
The VSAT peering would be considered an iBGP as there isn't a provider router in the middle of the connection as the MPLS-VPN.
While eBGP is preferred over iBGP when all attributes are being equal, on this case, the AS_PATH will be shorter on iBGP so those routes will be preferred.
You can configure a route-map on each router and use AS Prepending on routes being advertised for the VSAT neighbor.
router bgp 63590
neighbor [vsat_peer_router] remote-as 63590
neighbor [vsat_peer_router] route-map AS-PATH-OUT out
route-map AS-PATH-OUT
set as-path prepend 63590 63590
HTH,
__
Edison.
03-28-2008 10:51 PM
Thanks Edison
I have configured the same but still most of the route are learned by AD200 (iBGP). please help me out.
03-29-2008 01:03 AM
Try using the local preference / weight attribute to prefer the MPLS routes
router bgp 63590
neighbor <
neighbor
route-map local-pref permit 10
set local-preference 120
You need to configure it at both ends
HTH
Narayan
03-30-2008 11:42 PM
Thanka Narayan
but i think this will work when both the routes comming from iBGP.
weight attribute also i have configured but no change. I am thinking whatever attribute i am configuring is not allowed by sevice provider of MPLS-VPN.
am i right or not ?
03-30-2008 11:50 PM
It should work... can you post your configurations
The Local Preference and Weight attribute is local to your router to make a decision on the routing. It has nothing to do on the Providers MPLS VPN
HTH
Narayan
03-29-2008 06:17 AM
Did you configure the AS Prepend on all VSAT neighbors? Doing it on just one end won't work.
Can you post the portion of the config from the 3 routers ?
03-29-2008 11:47 AM
Ok, forget AS_PATH prepending. It won't work on this situation as they are iBGP neighbors. Please follow Narayan's advise and use local-preference instead.
Sorry for providing the wrong information before.
Regards,
__
Edison.
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