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