Failover how much complexity will it add?

Stef Walter stef-list at
Tue Nov 10 21:19:01 UTC 2009

adel at wrote:
> Actually thinking about this, I still need to understand the
> implications of not taking a full routing table to my setup.  So what
> is the likely impact going to be if I take partial instead of full
> routing table.  Would appreciate any feedback on this.  My
> organisation is only looking at using BGP as a means of failover
> between two separate upstream ISPs.  We are not an ISP.

I'm up against the same issue. I'm having a hard time understanding what
partial routes will accomplish in the following scenario.

Let's say we were BGP multi homed and accepting partial tables from two
top level ISPs (like Sprint, Cogent, Telia, AT&T whatever). Let's say
they get into a peering spat with another top level ISP. This results in
one of your upstreams not routing packets to one or more ASs.

In this situation, as far as I can tell, you'd want a full routing
tables from your upstreams. Without a full routing table how would your
router know that certain ASs are reachable through one upstream, but not
the other?

In this day of and age of wild-west, cowboy attitudes between some of
the biggest players on the Internet, does protecting against these
problems require a routing device that can handle multiple full routing
tables? It would seem so...



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