Optimal failover for dual homing ?

src386 · Tue Dec 08, 2015 5:30 pm

Hi everyone,
I need to connect my LAN with a remote LAN.
BGP is needed because there are many networks so static routing would be complicated. But no peering.
We need failover so each side has 2 routers, linked with a dedicated fiber to the other side.
Iif a fiber link goes down, traffic must be forwarded to the other router, so we use IGP with nexthop-choice= force-self between routers.

                                  +--------+                      +--------+
                                  |        |         fiber        |        |
                              +---+  R101  +----------------------+  R201  +---+
                              |   |        |                      |        |   |
                              |   +--------+   <--------------->  +--------+   |
                              |                      bgp                       |
                              |    ^                                      ^    |
+-----------+                 |    |                                      |    |                  +-----------+
|           |             VRRP|    |                                      |    |VRRP              |           |
|   LAN1    +-----------------+    |igp                                   |igp +------------------+    LAN2   |
|           |                 |    |                                      |    |                  |           |
+-----------+                 |    |                                      |    |                  +-----------+
                              |    v                                      v    |
                              |                                                |
                              |   +--------+                      +--------+   |
                              |   |        |         fiber        |        |   |
                              +---+  R102  +----------------------+  R202  +---+
                                  |        |                      |        |
                                  +--------+   <--------------->  +--------+
                                                     bgp
+               AS100                      +                      +                  AS200                    +
+------------------------------------------+                      +-------------------------------------------+

This link also describes the situation : http://www.cisco.com/c/en/us/support/do ... html#conf3

My questions are :
- Is it a good architecture for failover ?
- Can VRRP react when a fiber link is down ? Ie: R101 is the default gateway for LAN1 and is the VRRP MASTER. If the fiber link goes down, traffic will go to (and come from) R102, so this one should be VRRP master.

Thanks.