Limited Visibility

Geoff Austin gaustin at
Wed Jan 28 18:35:38 UTC 2004

On Tue, 2004-01-27 at 21:05, Stephane Bortzmeyer wrote:

> You only have two nameservers and they are in the same room. Not only
> it is poor redundancy (imagine a power failure in the building), but
> it also makes you very vulnerable to IP routing problems.
> All your nameservers are in the same autonomous system (13037) and,
> much worse, in the same subnet ( 
> Since you are a customer of a recent /8 prefix (, you may
> experience old and unmaintained BGP filters. Or there is simply a
> stupid routing problem which includes your prefix. You may use BGP
> looking glasses <URL:> to see your route
> from the ISP which have the problem. 
> But the best solution is probably to have nameservers in different
> locations.

Stephane, thanks for responding.

Clearly having both in the same location is far from ideal, but I had
only considered the resilience angle and not the routing one. 

Today I tried to reach the www server from one of the failing ISPs and
it could not find the site with However, when I enter
the numeric IP addess, i.e., it displays the page happily.

Does this indicate that there is no routing problem, or is it more
subtle than that?

More information about the bind-users mailing list