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BGP neighbors advertises a VIP HSRP route in addition to peers route

Louey
Level 1
Level 1

Hi all

I am facing a weird case. I do have two BGP sessions with two different routers (rtr2 and rtr3 from rtr1)  connected via a LAN.

rtr2   rtr3
*       *
*       *
******
   *
   *
 rtr1

rtr2 and rtr3 were running hsrp on this LAN and rtr1 had a static default route to the VIP. As it was creating routing issues in termes of redundancy I did BGP default-information originate and deleted the static default route so BGP can handle that.

The issue is that I am receiving two default routes from each router. One with the routers next-hop (rtr1 and rtr2 IPs) and one with the VIP as the next-hop advertised by both routers with a 100 local-preference. I don t have any BGP peering with the VIP.

I can workarround this issue by increasing the local-pref of routers but I dont understand why this is happening.

Any ideas ?

Regards

12 Replies 12

Hello
How are you peering between the three rtrs do they share the same ASN or have separate BGP domains?
Or are rtrs 2/3 in the same domain only, either way Rtr should chose just the one default to enter the GRT.


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Kind Regards
Paul

rtr2 and rtr3 are in the same AS.

Regards

Hello
So unless you have maximum-paths specified then as I stated only a single default should get entered into the global routing table of the RTR1

Can you share your bgp CFG please

All rtrs
sh run | sec router


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This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

Thanks for your answer. I do have maximum-path 2 enabled on rtr1 but the route from vip is not installed in the RIB because of the local-pref (-). Which I don't understand is why I do receive a route as a VIP as next-hop with no HSRP enabled on this LAN ( as I disabled it) ?

Hello


@Louey wrote:

Thanks for your answer. I do have maximum-path 2 enabled on rtr1 but the route from vip is not installed in the RIB because of the local-pref (-). Which I don't understand is why I do receive a route as a VIP as next-hop with no HSRP enabled on this LAN ( as I disabled it) ?


Based on what you have described you should not be receiving should a route, hence why i requested you post the bgp cfg of all 3 rtrs.

sh run | sec router
sh ip bgp
sh ip bgp summary
sh ip route bgp
sh ip bgp 0.0.0.0


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

the neighbor is static config  or it dynamic with listen group 
are you use any listen group 

I have 2 static BGP neighbor rtr2 and rtr3.

Thanks

are the connection is iBGP between these routers ??

ebgp

I will run lab and see, 
the next-hop must be same peer you config not VIP of far HSRP group
but let me check 

I run lab and as I guess, 
the next-hop is Peer IP you config there is no VIP
are you use some kind of route server ?? 
are you use unchange next-hop ??

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