Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

routes advertising

Hi all,

I have a cisco router 7507 and i have connected to different service providers with different bandwidths. i have 2 class C ips with me. I want to advertise a subnet(pls note: NOt entire calls C) to service provider A. so that i can get all incoming traffic to that perticular subnet is from service proider A. Remaining Class C ips to other service providers. How can I do this. Can I use route-maps. or any other solutions for this. Kindly give me some examples if you can.

thanks

4 REPLIES
New Member

Re: routes advertising

You will first need to check with your service providers and see what routing protocol they are running. The standard Internet protocol is BGP. Next you will need to check with them and see if they will ALLOW you to do this. Many Service providers will not allow you to feed them another vendors route.

i.e. if you have xxx.xxx.xxx.xxx and the supernet for this range belongs to AT&T

and you have yyy.yyy.yyy.yyy and the supernet for this range belongs to Sprint.

AT&T will most likely not allow you to feed them a partial Sprint route and vice-versa.

~rlc

CCNP, CCDA, CNE

New Member

Re: routes advertising

hi,

thanks for the response. No need to worry with my service providers. They will take whatever I feed to them. The ip addresses are my own. And I can able to feed as a complete Class C. My question is how to feed a subnet of class C

to a service provider. The service providers are ready to accept my advertisements in whatever fashion.

Thanks

New Member

Re: routes advertising

Of course you can do this. It depends a lot on the routing protocol that you're currently running. If you're using BGP4 then the process is pretty simple by adding 2 x static routes and advertise them to the appropriate neighbour. Don't forget that BGP only advertise what you want it to advertise. This is the beauty of BGP4. You can contact me direct on vincentn@mediamonitors.com.au. BTW, if you have been in contact with Cisco TAC then also let know what their methods are.

New Member

Re: routes advertising

of course you can do it, but u must know what routing protocol running between u with two ISP, if they running BGP4 with u, u can advertising two subnet int two BGP network command, and use route-map to two ISP.

For example:

route bgp xxx

network x.x.x.0 mask 255.255.255.128

network x.x.x.128 mask 255.255.255.128

nei y.y.y.y remote y

nei y.y.y.y route-map filterA

nei z.z.z.z remote z

nei z.z.z.z route-map filterB

acc 1 per x.x.x.0 0.0.0.127

acc 2 per x.x.x.128 0.0.0.127

route-map filterA

mat ip add 1

route-map filterB

mat ip add 2

if there is static route running between u with u ISP, u can ask them to advertising two subnet special.

115
Views
4
Helpful
4
Replies
CreatePlease login to create content