Distribution of default route of four different ISP in a WAN MPLS

[MARIA EUGENIA RUIZ]

We´ve a MPLS Network, there is a vrf, the Green vrf, in wich are the users, now we are going to have four connections to internet in each one we are going to be receiving the default route, but we want to control the use of that connections, so if you are an user in one PE your default route must be provided depending on the region in wich you are. We´ve route reflectors.

How can we make the distribution of the default route depending of the region in wich the user is, such that the PE_11 gets his default route from the PE_ 1 and not from the PE_3, and the users in the PE_13 gets his default route from the PE_3 and not from the PE_5.

If we put the four defaults route in the vrf green an let bgp works, the route reflectors are going to distribute de best route that they learn, so will be only one ”best” default route out of the four we are having, and we need to balance the traffic.

How can we solve this?

The equipment involved is 7613 with IOS 12.2(33)SRD3

[Vasilii Mikhailovskii]

Hello.

If your PE_1, PE_5, PE_6 and PE_3 use different RD for the vrf, RR would reflect all the "default gateways" as they are different in terms of VPNV4 prefix.

So, now you need a solution to prefer one PE over another. The best would be to use communities, like:

 PE_1 - injects 1:1
 PE_3 - injects 1:3
 PE_5 - injects 1:5
 PE_6 - injects 1:6

Now regions could have following routing policy:

 if community matches 1:1 then
   set local-pref 140
 elseif community matches 1:3 then
  set local-pref 130

...

Per region you would assign high LP for "closer" exit-point.

Now you have typical configuration per region and failover mechanism between them all.