[c-nsp] PBR and BGP Question

[Jason Ford]

We are sending the default routes via eigrp. BGP only runs on the border 
routers so using the BGP method probably won't work.

I was looking at filtering out a subset of customer outgoing traffic and 
sending it over a cheaper bandwidth provider but I did not want to send 
all traffic out one or the other ISP. With that said, that was why I was 
looking at PBR or route maps to make this work. The selected traffic 
would be within a /28 or /29 subnet if that helps.

Thanks for the response!

jason

Pete S. wrote:
> How are you getting the default route into your core?
>
> If your ISP border routers, and core are running iBGP, simply use the
> local preference variable in BGP to send out the prefered ISP.   If
> that ISP connection goes down, the next highest local pref will become
> the default.
>
> Depending on the routes you're receiving, and redistributing...If
> you're redistributing your BGP into an IGP, you can announce two
> default routes into your IGP, one with a higher metric, from each
> border router running BGP.  in case of ISP failure, your traffic will
> get up to the ISP border routers, and then hopefully have a more
> specific route between iBGP, if one ISP connection were down.  Traffic
> would then take its course back to the ISP border router with the
> active ISP connection.
>
> You can also play with EEM(I can't recall if its in the Sup1 or 2, but
> I'd wager no) to pull the default route from the isp border router, if
> the BGP session were to drop on that router, and then re-insert it
> when BGP session reconnects.
>
> --Pete
>
> On Jan 21, 2008 1:28 PM, Jason Ford <jason at chatinara.com> wrote:
>   
>> All,
>>
>> I have a need to direct traffic from within our core routers out a
>> specific BGP peer unless that peer is down. Here is the setup..
>>
>> customer network ---> core router 03 and core router 04 --------> border
>> router 01 and border router 02 ---------> our bgp peers..
>>
>> Basically, the customer is connected to two 6500's running eigrp
>> sessions with the border routers. The border routers are running BGP and
>> eigrp. Border router 01 has a BGP connection to ISP A and Border router
>> 02 has a BGP connection to ISP B.  All routers are meshed together via
>> GE. Core Routers are 6500's with sup1a/msfc2's fully upgraded with
>> memory (yeah.. I know it should be upgraded to a sup2) and the border
>> routers are 6500's with sup2/msfc2 also fully upgraded with memory.
>>
>> Ok, here is the question. If we would like to route all of the
>> customer's traffic out ISP B unless it is down, is a PBR on the border
>> routers identifying the source address and setting a next hop the best
>> way of doing this? We don't care which ISP the incoming traffic goes to
>> but want to control the outgoing traffic.
>>
>> Hopefully that gets the question across without a network diagram.
>>
>> Thanks for all who read and respond.
>>
>> jason
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