[c-nsp] Internet Maintenance Traffic Manipulation

[Pete Templin]

On 6/8/11 11:35 AM, Mark Mason wrote:
> This post would be for those of you in a DC environment with multiple
> internet feeds. When carrier X emails about a 12:00 - 6:00
> maintenance window for IOS upgrade, reboot, card swap, etc. are you
> influencing your eBGP traffic away from that carrier during the
> maintenance window? Alternative being DO NOTHING and take the hard

In my past life as an NSP operator, I would always push traffic away 
from the affected link/carrier before the maintenance and restore 
default behaviors at sunrise or similar.  Fearing uRPF and believing in 
stability where possible, I would change the inbound route-map and wait 
~15 minutes (or until 'sh int POSx/y | i rate ' showed essentially no 
outbound traffic), then change the outbound route-map and call it a 
night.  In the morning, I'd reverse the sequence but would typically 
shorten the delay towards four minutes or so.  Management and customers 
were COMPLETELY oblivious to any carrier maintenance for years, 
including VPN activities.

Biggest tip is to write a set of route maps for maintenance "right away" 
and leave them on the router.  In my case, we had two connections to 
each of three carriers, so I had -highmed route maps standing by for 
single-connection maintenances (-maint was for multi-site maintenances).

pt