[c-nsp] Failover with multiple upstreams running BGP

[Junaid]

Hi,

I need advice on how to have a fast converging failover from my
upstream Internet providers. I am an ISP with three Internet upstream
providers. I am running BGP with them. Currently I am load sharing my
Internet traffic by advertising some of my /24s via one ISP and some
via the others. However, as a backup, I advertise the supernet(s) via
all links so that in case one of the links go down, traffic should
return via the supernet. But it seems that after one /24 advertisement
stops reaching the Internet, traffic of that prefix comes via the
supernet advertisement after quite a while (even upto 30 mins). What
is the reason for this behavior and how can I design for a faster
convergence in such a case (i.e. one of my upstream link goes down)?

Thanks.

Regards,

Junaid