nslookup failed externally

[Barry Margolin]

In article <9l18l0$q6j at pub3.rc.vix.com>, Sylla <masylla at hotmail.com> wrote:
>Twice within a period of 2 months we had been experiencing this
>problem in a middle of the day. Nobody was able to resolve any domain
>name externally. However we were able to resolve names using one of
>the root servers ip address. This lasted for few minutes and things
>went back to normal. We have 3 DNS servers internally and 3 DNS
>servers in the DMZ(behind the firewall).
>The firt time it happen, we thought it was a firewall issue, but
>yesterday when it happen again, I called the firewall SA's and they
>were not experiencing any problem on their side. We did ndc restart,
>but that did not fix the problem.
>There was no error in the log file either. We running BIND8
>Does anyone experience this problem before?
>Your feedback is really appreciated.

It's impossible for us to tell what happened to you.  Did you try putting a
sniffer on your LAN to see where the DNS queries were going?  Are the
internal DNS servers configured to use the DMZ servers as forwarders, or do
they go out to the Internet themselves?

-- 
Barry Margolin, barmar at genuity.net
Genuity, Woburn, MA
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