[c-nsp] iBGP peerings timing out

[Kevin Barrass]

Hi

On a test setup we have below,

ISPR1  ISPR2
|      |  <--- point to point ethernet links
|      |
R1     R2
|      |
|      |
---------vlan100---------- <--- resilient ethernet backbone
   |                |
   |                |
   R3               R4

R1 has eBGP peering to ISPR1 and R2 has eBGP peering to ISPR2. all
routers R1-R4 have iBGP peerings to each other. We are running EIGRP
only for the loopback addresses of the routers R1-R4 and the next hop
addresses to the ISP Routers 1 and 2.

We receive only a default route from both ISPR1 and ISPR2 which is then
passed to our other BGP routers over iBGP. We are not currently
re-distributing that default into EIGRP for this test.

If R1 fails "i.e. blows up" how long will it take for routers R2-R4 to
know that the default route R1 was advertising over iBGP is no longer
valid. The way I understand it is that it would take either 3 * 30
seconds for the iBGP peer to time out or 1 minute for the next hop for
routes advertised from R1 to be un-validated due to the next hop to
ISPR1 dropping out of EIGRP is this the case.
If there is still a default route available will that mean that the next
hop to ISPR1 is still valid from iBGPs point of view.
Any advise on this much appreciated.

Kind Regards
Kev