Please help our simple bgp

Jared Mauch jared at puck.nether.net
Tue Jan 31 08:20:17 CST 2012


On Jan 30, 2012, at 9:27 PM, Ann Kwok wrote:

> Hello
> 
> Our router is running simple bgp. "one BGP router, two upstreams (each 100M
> from ISP A and ISP B)
> We are getting full feeds tables from them
> 
> We discover the routes is going to ISP A only even the bandwidth 100M is
> full
> 
> Can we set the weight to change to ISP B to use ISP B as preference routes?
> 
> Can the following configuration work?
> What suggest to this weight no. too?
> 
> neighbor 1.2.3.4 description ISP B
> neighbor 1.2.3.4 remote-as 111
> neighbor 1.2.3.4 weight 2000
> 
> If this works, how is ISP B upstream connection is down?
> 
> Can it still be failover to ISP A automatically?
> 
> If it won't work, Do you have any suggestion?

Please implement an AS-PATH filter on your outbound to your
upstreams blocking yourself from re-annoucing their routes to them.

You can see many of these cases here:

http://puck.nether.net/bgp/leakinfo.cgi

eg:

41.217.236.0/24 852 3561 6453 15399 15399 15399 174 3491 33770 36997 37063 37113

15399 (Wananchi Online Limited) is leaking their upstream (Cogent) routes to TATA (6453)

- Jared


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