Re: DNS not forwarding to other dns servers
Massimo Rosen
asalazar wrote:
>
> We had a problem the other day when we lost power on our external DNS
> server. Users out on the internet were not able to hit our website and
> do any resolutions to our Secure VPN gateway. When we used the URL
> address for the website it would not resolve. When we used the VPN
> Client it would not resolve the name to an address to access the VPN. If
> we used the IP address it would work.
>
> I was under the impression if my dns server went down anyone trying to
> resolve address to my domain would get the resolution from their DNS
> server since this information was cached in their DNS Server.
Only as long as the TTL hasn't expired, and that could happen basically
within minutes after your server is down, depending on when the other
DNS server has contacted your server last. E.G, if the TTL of your zone
is 12 hours, and a DNS server on the internat has contacted you last 11
hours and 50 minutes ago, 10 minutes into the outage that server will
stop resolving names for you. Or, of course (and that's even more
likely), that DNS server hasn't cached your data at all.
> My forwarders are pointing to DNS server downstream on our Cable modem.
That's completely unrelated. If you want your DNS to be more reliable,
you need a secondary DNS server elsewhere, potentially one of your ISP.
CU,
--
Massimo Rosen
Novell Product Support Forum Sysop
No emails please!
http://www.cfc-it.de