topic Re: opening port in Operating System - HP-UX

opening port

PRUSZEK Nicolas — Thu, 06 Aug 2009 06:31:10 GMT

Hello,

I've 2 HP servers.
First server, 6535 port is opened

netstat -an | grep 6535
tcp 0 0 10.169.33.138.6535 *.* LISTEN

but nothing in file /etc/services

How to open this port 6535 on the second server?
thanks

Re: opening port

Jeeshan — Thu, 06 Aug 2009 06:40:59 GMT

If it's not mentioned the port name in /etc/services file then, the port is opened by the process or software.
check with lsof in server 1 that which process's using port 6535

Re: opening port

PRUSZEK Nicolas — Thu, 06 Aug 2009 06:48:09 GMT

Here the result

lsof | grep 6535
CFTTCPS 19547 syscft 9u IPv4 0xe0000001e28a43c0 0t0 TCP su1241cli.sfr.com:6535 (LISTEN)

Re: opening port

Steven Schweda — Thu, 06 Aug 2009 11:07:13 GMT

> If it's not mentioned the port name in
> /etc/services file then, the port is opened
> by the process or software.

If a service (port) name _is_ mentioned in
the "/etc/services" file, then some program
still needs to run (or to be registered with
inetd, so that inetd can run it) to give you
that "LISTEN". It's easy to write a program
which will listen on some port, but which
never looks at "/etc/services".

Some people seem to have a greatly inflated
idea of what "/etc/services" does. This
leads to many useless suggestions involving
changes to "/etc/services".

Re: opening port

Steven E. Protter — Thu, 06 Aug 2009 11:38:12 GMT

Shalom,

I describe /etc/services as a reservation file.

Some services require it to be configured to work. Oracle an the other extreme totally ignores it, which is IMO bad practices.

You seem to have an unexpected service running on that port on the second server. Port conflict.

SEP

Re: opening port

Fred K. Abell Jr._1 — Fri, 21 Aug 2009 12:14:59 GMT

It could be a back door listener. Probably not with a 10 *.*.* address, but maybe an inside user opened a port. Try

ps -ef | grep nc

to see if netcat is running.

Fred