Multi Home BGP

[taufeeq taufeeq]

Hello,

Kindly please help me!

We have 3 DIAs connections from the single ISP. We have only one router in our network for internet.

We have our own public BGP AS & /22 network. there is same neighbor BGP AS for all these 3 DIAs.

As of now its load balancing with the help of the command 'maximum-paths 3'

Is there anyway I can tell my router to use different DIAs for different subnets for internet access.

I want DIA1 to route traffic from public subnet 185.x.1.x

DIA2 to route traffic from public subnet 185.x.2.x

DIA3 to route traffic from public subnet 185.x.3.x

Note: ISP is accepting /22 prefix from us.

[Mark Malone]

You could use a route-map match against certain subnets and alter the bgp attributes for those specific subnets so they only go down the internet circuit or match with a route-map against subnets and set the next-hop ip to be the internet circuit

examples in this doc , few ways to do it depending on the attributes in place

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3se/3650/irg-xe-3se-3650-book/irg-prefix-filter.html

[trfinkenstadt]

Will the isp only accept a /22 from you or will they accept the /24s?  It would seem to me you need to do a combination of policy-routing to get your traffic to leave the path you want to the ISP and some BGP metric manipulation of what you send the ISP either via MED, AS-PATH, etc.

best regards,

tim