michael@??? probably said:
> All your arguments are correct, but I think I should elaborate. I am
> not against cache hierachies, but I advise not to use a DNS server with
> local domains as forwarder. If domains move to new name servers, using
> a forwarder to the local server will still resolve the old zone. Using a
> cache that resolves via root name servers will use the correct zone ASAP
> which is usually earlier than when your hostmaster changes named.conf.
I don't mix auth and caching name servers.
> Honestly, with 16 GB mail traffic a day, I doubt the extra lookups cost
> me much bandwidth. Further, it takes a much longer time to detect that
The last time I measured it it was significant enough to me. It would
certainly be significant enough in my current position.
Which reminds me, once I set up a machine on a monitor port on our main
netlink I should calculate how much of our bandwidth is being used by
people running their own caches (which we don't disallow, I'd just
prefer it if people used mine).
> a remote name server that you use as forwarder is down. That happens
> only rarely, but it can kill a busy system.
That also depends on many things. You should only get a slight delay.
(if this actually happens or not depends on many things).
> So the answer probably is: It depends if a local DNS cache is useful.
> There is more to think about than just resource usage.
There always is.
P.
--
pir pir@??? pir@???
