I have a relatively complex problem that has brought me to the limit of
my limited knowledge.

History: I have a BM 3.5 server running on NW 5.0. I am patched. It has
been running for years. I have a linux cluster running qmail. All traffic
from the internal network passes through the cluster and then through BM
to get to the internet (dedicated connection). BM is running NAT (static
and dynamic), firewall and proxy services.

Monday things changed. Now everyday I arrive in the morning and mail is
mounting up on the cluster. If I unload ipflt on BM nothing changes. I
can't telnet to any 25 or 80 port from the mail server. All services stop
that use TCP. I have a squid server in test right now. This server has a
statitic NAT address. That machine (and others) can ping addresses using
DNS on the internet (with ipflt unloaded) but can not browse or send mail.

I am monitoring my internet router (it is outside the BM server) via MRTG
and snmp (UDP) from a machine on the internal network. This does not stop

The proxy on BM continues working perfectly.

Routing has not presented any noticible problem.

Summary: Every morning all TCP services running behind BM stop working.
UDP and ICMP continues. I have unloaded NAT and reloaded to no avail. The
only solution seems to be the restarting of BM. Once I do that everything
starts up again.

How do I trouble shoot a TCP problem on BM? This is probably the oddest
thing I have seen. Quite frankly I'm not sure if it is BM (NAT). This
maybe a basic Netware problem.

Any thoughts would be extremely appreciated.