BGP Multihomed to One ISP

CSCO11177789 · ‎02-01-2009

Hello;

We have two 7206 VXR thats connected to one isp over two metro ethernet lines.

One of them use 30mbit the other one is 50 mbit. We use bgp in our environment to connect internet.

We configure route-maps.

For example i have two network like 194.12.12.0/24 and 194.12.13.0/24.....When i configure route-map with "set as-path prepend", i managed to network route origin internet and load-sharing between two 7206. As you know prepend is route-map out filtering.

As same as route-map out filter i want to use load sharing between two 7206 while connect to internet.

For example 194.12.12.0/24 network has to use 30 mbit or 194.12.13.0/24 network has to use 50mbit while connecting to internet.

Which route-map in attribute should i use for this kind of connections ?

Thanks.

Giuseppe Larosa · ‎02-01-2009

Hello Umut,

to influence how from two client Vlans you go to the internet you can work on the interior routing:

if these two subnets are directly connected to the two border routers you can implement two HSRP groups one in each subnet and you can give priority (active role ) to the router connected to link n.1 and to the other router on the other subnet.

If the subnets are more internal you need to implement PBR on the internal router(s) so that traffic with source 194.12.12.0/24 will be passed to first border router and packets with source 194.12.13.0/24 will be sent to the other one.

Normal destination based routing cannot help in this case

Hope to help

Giuseppe

CSCO11177789 · ‎02-01-2009

Hello;

Actually, in our network we use checkpoint cluster firewall with 6 zones. So while connecting the internet we use static or hide NAT on firewall for servers or ip groups. So we think, networks that i told in my first mail on firewall.

Also firewall default route is HSRP address of 7206's internal interface like 194.12.13.254. i say internal interface but because of in front of the firewall all ip are real like 193.12.12.0 / 24 or 193.12.13.0 / 24.

Could i still use PBR or HSRP ?

Thanks.

paolo bevilacqua · ‎02-01-2009

I think you can use MED since you're multihomed to the same provider. If MED works as intended it can make use of prepend as-path unnecessary.