Master/slave configuration

[romgo at free.fr]

Dear community,

I use bind on my network as DNS Server. Running bind 1:9.6.ESV.R4+dfsg-0+lenny4
on Debian Lenny.

The setup is quite usual : one master server with one slave server.

The slave sync the zone from the master.

I discover that when the master is down I have some trouble to access to
internet and to local domain which are managed by the master server.

Symptoms are : slow browsing and some website can't be reached, seems to be a
timeout issue. (the server didn't answer in time).

I saw that for unreachable website, the issue was DNS as my tcpdump didn't get
any http request.

How can I troubleshoot this issue ?

Regards,