North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: Disaster recovery using as-prepend?

  • From: Todd Vierling
  • Date: Fri Feb 17 15:57:06 2006

On Thu, 16 Feb 2006, Warren Kumari wrote:

> If your primary is connected to ISP_A and the backup is connected to ISP_B,
> customers connected to ISP_B MAY still flow to your backup DC (ISP_B will
> probably set local preference on all customer routes - you should be able to
> override this behavior with communities but not all providers support this (or
> honor it 100% of the time!))

And in addition to that, even multihomed customers of ISP_B may choose the
prepended route for a number of different reasons; for instance, ISP_B might
be a cheaper pipe for them, or there may be a smart-ish routing device or
scheme in play that overrides normal BGP decision making.

-- Todd Vierling <[email protected]> <[email protected]> <[email protected]>