Re: .ORG problems this evening

[Alex Bligh <alex () alex org uk>]

--On 18 September 2003 10:05 -0400 Todd Vierling <tv () duh org> wrote:

> DNS site A goes down, but its BGP advertisements are still in effect.
> (Their firewall still appears to be up, but DNS requests fail.)  Host
> site C cannot resolve ANYTHING from DNS site A, even though DNS site B is
> still up and running.  But host site C cannot see DNS site B!

What you seem to be missing is that the BGP advert goes away when the DNS
requests stop working.

I have written DNS/BGP code (nothing to do with UltraDNS) and I can tell
you it works very well. Even if you unplug the machine from the net you can
get rapid failover by tweaking a BGP timer here or there. If you are going
to say "yes but that means I don't have one of the servers up whilst
routing reconverges" this is true, but (a) it happens ANYWAY, (b) as the
prefered route is in general more local, the "rainshadow" from routing
reconvergence in the event of disruption is smaller.

Alex