IGP choice

[dcorbe at hammerfiber.com (Daniel Corbe)]

"marcel.duregards at yahoo.fr" <marcel.duregards at yahoo.fr> writes:

> Hi everyone,
>
> Anybody from Yahoo to share experience on IGP choice ?
> IS-IS vs OSPF, why did you switch from one to the other, for what reason ?
> Same question could apply to other ISP, I'd like to heard some
> international ISP/carriers design choice, please.
>
> Thank in advance,
> Best regards,
> -Marcel

I worked a project as recently as 2009 where we tried to connect two
6509s together over a tunnel interface and wanted to extend Area 0
across it and couldn't because it was a limitation of the version of IOS
we were running at the time.

That forced us to use isis.

It was a decision based on pragmatism rather than design choice; and we
were a small operator, too.  The choice of an interior routing protocol
really doesn't have much implication for small operators.