Re: How common is lack of DNS server diversity?

[lucifer () lightbearer com]

Thomas Kernen wrote:
> And what happens if the 4.0.0.0/8 route is flapped from the
> routing table? No more DNS. So you still want route diversity
> that isn't in the same block or aggregated block.

You know, some folks simply decide that, for the cost and complexity of
managing a box in someone else's space (not to mention potential security
issues, et al, for some) that the loss of DNS server is fairly irrelevant
if the entire rest of their netblock is offline.

"Gee, DNS says that www.joebobsisp.com is over here... but I can't get
there with the route yoyo-ing like mad". Have you *really* gained much,
in this situation?

(Note that I'm not claiming in the least that there aren't situations in
which having off-AS servers is worthwhile, and if you have multiple ASes
from aquisitions or the like, it would certainly seem wise to make use of
that fact, but there ARE issues, and for some number of folks, those
issues can easily outweigh the (often limited) benefits gained...)

<Soapbox>

Remember: one of the most important things about knowing the rules is that
it makes it possible to evaluate whether breaking the rules is worth the
consequences.

</Soapbox>
-- 
***************************************************************************
Joel Baker                           System Administrator - lightbearer.com
lucifer () lightbearer com              http://www.lightbearer.com/~lucifer