External Access Dies

[Neal Burt]

L1000 running 11.0,
the unix box is in DMZ, connectivity to internal workstations is maintained, however, the external connectivity dies at five (5) minute interval. I restart the netserver and five minutes later the external connectivity disappears. I have run through every troubleshooting flow chart I can find and see nothing amiss. Main application running on this machine (standalone server) is SIRSI, a propprietary library services application.
Any suggestions?

[Jeff Schussele]

Hi Neil,

Sure sounds like a time-out or idle-out situation.
First thing I would do is take a look at the external firewall logs and config.

Rgds,
Jeff

[Neal Burt]

Firewall shows traffic in to unix box and out during the initial 5 minutes...then no traffic out. The other servers (NT 4.0 and Win 2000 (:( ) have traffic in and out of DMZ...Just found the thread on the dead gateway probe, am trying that now. Thanks for your quick response, will assign points just as soon as I can figure out how.

[Jeff Schussele]

I assume this is port 80 - Web - traffic we're talking about here?
Are you doing any kind of load balancing - either HW or SW?
Any messages logged in /var/adm/syslog.log and/or the application logs to work with?
Any way to turn up the logging level on the web server SW?

If not, I suspect you'd have to get a sniffer going here & start analyzing packet traffic when the problem occurs.

Rgds,
Jeff

[Jeff Schussele]

OH...and one other thing.
You can do a
netstat -an
and look at the output - you'll probably want to grep down to the relevant IPs / ports.
I suspect something is leaving the sockets "hanging", possibly in a FIN_WAIT state.
If that's the case then no more traffic will come out of the HP as it's waiting for something to come in. I've seen HW load balancers do this. They send an RST (reset) when the HP is looking for a simple ACK.

Rgds,
Jeff

[Neal Burt]

Thanks for all the help...solution to problem was to turn the ip_ire_probe off. See Subnet conf. on HPUX 11.0 thread.
Thanks again for everyone's assistance.