[c-nsp] BFD + BGP on 7600 SRC or SRD

[Walter Keen]

I am looking to use it on vlan interfaces, I have one with 12.2(33)SRC2 
and it appears to support the option in the config, but I wanted to know 
if there were known bugs before I deployed it.


We have a situation where a peer currently connected via bgp at two 
locations has traffic routed to our voice softswitch, and are trying to 
provide an almost-realtime cutover between our two links to them in the 
event of a fiber cut.

example topology

CM
  |
  /\
A   B
 |    |
 C--D---SS

Forgive the bad ascii drawing.  CM is the partner's CMTS, running eigrp 
between CM and A/B, all within their AS.  Details of how many routers 
are between CM and A/B is unclear.
C and D are our 7600 series routers, with a BGP link to A/B 
repsectively.  C is connected via an electrical 100mbit connection, 
where the D portion of C->D and B->D is a Gig-E metro-ethernet 
connection, with the BGP session in a vlan (hence, if the fiber to D 
gets cut, B is unaware that the link is down until the bgp hold timers 
expire)
SS is our softswitch, and there are voip cablemodems on the partners 
cmts (CM).  In the event of a fiber cut to D, we want as fast of 
failover to the link through C as possible.  There is also another route 
from C to D through another network, routing across it is not a problem, 
OSPF seems to do a decent job of that.

The partner also is set on doing either static routing or BGP, and not 
wanting to introduce any other protocols into their edge routers for 
peering.

What is the best option for this scenario?  In the interim I've lowered 
the BGP timers so we have a hold time of 15sec, but that still means 
dropped calls.
 





Justin Shore wrote:
> Walter Keen wrote:
>> Hi, I'm looking at using BFD with BGP on 7600's (rsp720's and 
>> sup720-3b) and was wondering if there were any known issues with 
>> certain IOS's in the SRC or SRD train.
>
> BFD support for SVIs was removed with SRB2 if that's something that 
> you think you'll need.
>
> Justin
>

-- 


Walter Keen
Network Technician
Rainier Connect
(o) 360-832-4024
(c) 253-302-0194