topic Re: telnet issue in Operating System - HP-UX

telnet issue

kunjuttan — Fri, 10 Jun 2011 09:45:39 GMT

Hi All,

I am facing one problem in one of our server.If I am trying to telnet to one of our server using port number,it is giving an error.How to solve this issue.

#telnet 172.16.8.164 3301
Trying...
telnet: Unable to connect to remote host: Connection refused

But If I am trying to connect using other port it is getting connected.What to do?
#telnet 172.16.8.164 3300

OS Version is HP-Unix11.31

Re: telnet issue

g3jza — Fri, 10 Jun 2011 09:51:22 GMT

Hi,
well, that port is either not allowed to be accessed from your station (firewall) or it's not even listening on the server.

Check it with your network admin, if there are any restrictions.

Re: telnet issue

g3jza — Fri, 10 Jun 2011 09:52:15 GMT

or try from the server:

#telnet localhost 3301
if the service is listening on the given port

Re: telnet issue

Laurent Menase — Fri, 10 Jun 2011 10:05:59 GMT

you could check also with a netstat on the server

and if you well a listening socket on port *:3300 , then there is a firewall between you and the server.

The other option si that listenqueue is full.

Re: telnet issue

kunjuttan — Fri, 10 Jun 2011 10:42:49 GMT

Thanks for the update.Network Team is saying that the port is enabled from the firewall side.From server side we need to open the port and make it to listenable mode.How can I do that?

Re: telnet issue

g3jza — Fri, 10 Jun 2011 10:44:50 GMT

the application should be responsible to open that port and listen on it.

Re: telnet issue

Laurent Menase — Fri, 10 Jun 2011 10:47:25 GMT

I am afraid it depends on your application.

you can check if any application is listening
with a
netstat -an |grep LISTEN |grep '\.3300 '

Re: telnet issue

kunjuttan — Fri, 10 Jun 2011 10:56:24 GMT

# netstat -an |grep LISTEN |grep '\.3300 '
tcp 0 0 *.3300 *.* LISTEN

# netstat -an |grep LISTEN |grep '\.3301'
#

Here for port 3300 its is showing listening and I can able to telnet using 3300.But I cant do it using 3301.In the netstat command also it is not giving any output.
How can I enable the port 3301 to listen state?

Re: telnet issue

g3jza — Fri, 10 Jun 2011 11:01:34 GMT

It's the role of the application to assign port numbers. Check any configuration files of the application , maybe you can define, where the application should listen (on which port / ports).

Re: telnet issue

Laurent Menase — Fri, 10 Jun 2011 11:02:02 GMT

what application would you like to listen on port 3301?

Re: telnet issue

kunjuttan — Fri, 10 Jun 2011 11:17:40 GMT

We are using SAP

Re: telnet issue

Laurent Menase — Fri, 10 Jun 2011 11:32:35 GMT

look at that
http://forums.sdn.sap.com/thread.jspa?threadID=1571340

you just need to configure RFC
gateway service: sapgw01

if it is RFC you want to listen to port 3301