[c-nsp] slow convergence on edge BGP routers

[jure brkljacic]

Hi,

We have two bgp routers with full bgp table. All traffic is forced over
router EDGE1(from EDGE2 and "internal" router).

When i shutdown the "upstream link" on EDGE1 all the traffic is rerouted to
EDGE 2 router, but i see 15sec complete outage. (the path the end system
takes in "internal router" ->>EDGE1->>EDGE2)

a.) BFD enabled on all interfaces (bgp neighbor is immediately torn down)
b.) no input queues on EDGE 1 during the convergence
c.)EDGE routers are ASR1004 with RSP2


how to minimize the traffic loss?


      |                           |
      |                           |
      |                           |
+-----+-----+            +-----+-----+
|              |            |               |
|  EDGE1 ----------------EDGE2  |
|              |            |               |
+----+------+            +--------+--+
     |                             |
     |                             |
     |                             |
     |                             |
     |                             |
     |                             |
     |                             |
     |        +----------+       |
     |        |             |       |
     |        |             |       |
     +--------+Router+--------+
              |             |
              |             |
              +----------+