Cisco Support Community
Community Member

Force certain subnets via one link

We have just purchased a third Internet Connection(Open Pipe) from one of our Upstreams (primary_upstream_A)

We are going to maintain our current 10M connection to primary_upstream_A and a 20M connection

to primary_upstream_B for 'premium' paying customers - Giving them redundant paths etc.

I want to force certain subnets(Clients wanting a budget connection) to only use this new third connection.

Our 7206VXR is doing one-armed routing - All connections are Port-channel subinterfaces.

Proposed conf:


router bgp xxxxx

no synchronization

bgp log-neighbor-changes

bgp deterministic-med

network mask

neighbor primary_upstream_A peer-group

neighbor primary_upstream_A remote-as xxxx

neighbor primary_upstream_A soft-reconfiguration inbound

neighbor primary_upstream_A distribute-list DEFAULT_ROUTE_IN in

neighbor primary_upstream_A route-map AGGREGATE_OUT_PREPEND out

neighbor primary_upstream_B peer-group

neighbor primary_upstream_B remote-as xxxx

neighbor primary_upstream_B soft-reconfiguration inbound

neighbor primary_upstream_B distribute-list PREFIX_OUT out

neighbor primary_upstream_B route-map PREFER_UPB_IN in

neighbor Open_Pipe peer-group

neighbor Open_Pipe remote-as xxxx

neighbor Open_Pipe soft-reconfiguration inbound

neighbor Open_Pipe distribute-list DEFAULT_ROUTE_IN in

neighbor Open_Pipe route-map unlimited-traffic out

neighbor peer-group primary_upstream_A

neighbor zzz.zzz.zzz.zzz peer-group Open_Pipe

neighbor yyy.yyy.yyy.yyy peer-group primary_upstream_B

no auto-summary



ip prefix-list unlimited-traffic-prefixes seq 10 permit unlimited_traffic_subnet/24

ip prefix-list unlimited-traffic-prefixes seq 100 deny le 32



route-map unlimited-traffic permit 10

match ip address prefix-list unlimited-traffic-prefixes

set ip next-hop open_pipe_connection_ip


ip access-list standard DEFAULT_ROUTE_IN

remark Allow all from BGP peers

permit any


What I'm hoping the above will do is:

- Force anything with a source address contained within unlimited_traffic_subnet/24

to go out via open_pipe_connection_ip

- Advertise unlimited_traffic_subnet/24 via open_pipe_connection_ip - And

as it is a more definitive route than our aggregate advertisement

( to both our primary_upstream_A and primary_upstream_B Links, traffic

*should* return via the Open Pipe connection.

Am I on the right track here? Or is there another way to achieve this?



Community Member

Re: Force certain subnets via one link

CreatePlease to create content