Multi home BGP and static routes

Unanswered Question
May 9th, 2008

I have a router that has multihome BGP running on it. I was told that since we are running multihome BGP I need to create a static route for this to work.

Well I did that but I don't think I did it right as now the routes aren't learn via bgp but via static route. Attached is my config along with the static routes commands. The one highlighted in blue is the one I'm concerned about. I take the static route out and I cannot ping

I have this problem too.
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Rick Morris Fri, 05/09/2008 - 10:20

That is correct, you need to have static route pointing to a null0 or loopback interface.

in the bgp config you then can use the redistribute static, this will put those routes into the bgp announcement.

wgranada1 Fri, 05/09/2008 - 10:27

ok I must not know how to look things up

I was trying to find something like this but wasn't able to thus the post. Thank you sir!!!! this is what I was looking for will read it and implement it. Thanks again!!!!!!

Rick Morris Fri, 05/09/2008 - 10:37

I understand what you are saying. Everytime I look for something I never find it, then post what I need and someone finds it.

I just did a search on BGP Sample Configurations on

wgranada1 Fri, 05/09/2008 - 10:55

Sorry maybe I explained it wrong I have a single router that has mutlihomed BGP connections on it. The connection is not directly connected I can get to it if I put a static route via the ethernet address using my loopback address as the update sourece. I have the static route how do I get it to advertise over the BGP connection I read over the link but maybe I'm missing something.

Rick Morris Fri, 05/09/2008 - 11:05

a static route will ensure that the route will never go down, if pointing to null0, and will make sure that the route will always be announced, it also helps with route flapping too. Keep in mind that the router has to have some way of knowing how to get to the network. If the router does not know how to route it will not be announced.

It is not a requirement but a good practice. I have had this issue and not 100% sure why it happens, I just know that if my routes do not announce I add the static route of the block pointing to null0 and it forces the redistibution of the route.

wgranada1 Fri, 05/09/2008 - 11:20

Sorry I just confused myself completely. Ok so what you are telling me is that because I have a single router that has multihomed BGP connection I will need to add a static route for this connection. I'm peering with AS64637 and address of and to get to that IP I need to go through the ethernet address of So I will need a static route to point to that:

ip route

now all I need to do is redistribute that into BGP so that the peers will connect

right? So inorder for me to redistribute I need to do something like

redistribute static

This will go under my BGP statements. Thanks for putting up with me I appreciate it!!

Rick Morris Fri, 05/09/2008 - 11:26

I would recommend pointing the static to null0

ip route null0

router bgp XXXXX

redistribute static

then verify the announcement

sh ip bgp neigh x.x.x.x adv

This will show you which routes are being advertised to this neighbor.

You might want to use a prefix-list and route-map to specify this announcement out the correct neighbor unless you want this announced to all peers.

does that make sense?

I am a little rusty with BGP, been a few years since I have had to look at it, like 4 years

Rick Morris Fri, 05/09/2008 - 11:19

not sure if this explains it but saw this and thought it was interesting to note

router bgp 10

neighbor remote-as 11

neighbor update-source loopback 0

!--- Use the IP address of the loopback interface for TCP connections.

neighbor ebgp-multihop

!--- You must configure ebgp-multihop whenever the eBGP connections

!--- are not on the same network address.

router eigrp 12




no auto-summary

Note: You can use static routes in the place of a routing protocol in order to introduce two equal-cost paths to reach the destination. In this case, the routing protocol is EIGRP.

wgranada1 Fri, 05/09/2008 - 12:09

You know what the is a route advertised by the distant end and not me I have maybe if I'm still confused I will open up a TAC case as I have taken up enough of your time.


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