HP Server Couldn't communicate with a web server

[Jie Li]

Folks:

We use a company to provide a web service to our customer. The Company host the web server for us. The web server need to access the database on our HP server to retrieve info. About two weeks ago, the web server couldn't communicate with our HP server anymore.

Our HP server is sitting behind a firewall. The firewall has the IP's and ports open for the web serve to access our HP server.

Could you please suggest a way to test & to nail the problem? I checked with our Network folks, they said the firewall is open. I tried traceroute. Traceroute couldn't even get out of our HP server's domain.......

[Florian Heigl (new acc) · Accepted solution]

the traceroute in itself is probably in trouble by Your network people not allowing icmp echo replies and such. this, though questionable, is a regular setup.

do You have some auditing that would show the webserver's accesses over the period?

[Uday_S_Ankolekar]

Is default gateway set properly on your HP server.
If yes, can it ping to the gateway ( It should be a router in your network.

netstat -in will show you your default gateway details.

/etc/rc.config.d/netconf file has configuration details.

Also check firewall for ICMP settings for your server and Web server

-USA..

[Jie Li]

Other company is hosting this perticular web page, so we don't really have track of it. What kind of history would help me determine what's wrong with it?

Thanks

[Jie Li]

Yes, I can traceroute to the gateway.
However the web server has ICMP disabled.

[Mel Burslan]

ps -ef | grep inetd

if you see /usr/sbin/inetd -l in the output you are in good shape. if not, i.e. you only see /usr/sbin/inetd, then you need to restart it with logging enabled first. To do this:

/usr/sbin/inetd -k
/usr/sbin/inetd -l

now your inetd is logging events into your syslog. watch your syslog with

tail -f /var/adm/syslog/syslog.log

while you or someone from this external service provider is creating some traffic heading for your internal server and see if anything is getting logged in the syslog.

if so, post the messages here to determine what is happening. If nothing gets logged to syslog, contact your firewall admins to put a sniffer between these two servers to see what is going on.

[Jie Li]

inetd is running. Everything on the HP server still working, except the connection between the hp and web server

[Mel Burslan]

you did not understand my question obviously. I am interested in what inetd messages are getting logged in your syslog. They may tell us more details. And lack of any messages may mean they (external web service providers) are not able to access your server at all.

this is what you need to make sure, i.e., the packets/requests from these external guys, are hitting your internal server. And in short of putting a sniffer down the line, all you can do is watch syslog or run

netstat -an | grep port_number

commands like crazy to see if they establish any successfull sessions with your server, where port number is the port your server is listening to these guys requests.

if you can not provide this log data, you will not be able to get help magically.