Problem to telnet Red hat server

berndbausch · 11-18-2015, 03:08 AM

Quote:

Originally Posted by Huamin

Thanks. Any advice to the following?

[oracle@hpi5 sbin]$ iptables -S
bash: iptables: command not found
[oracle@hpi5 sbin]$ ss -lntp | grep 8000
bash: ss: command not found
[oracle@hpi5 sbin]$
[oracle@hpi5 sbin]$ lsof -i :8000
bash: lsof: command not found

according to the given advice on #4 and #5.

Your system is missing essential software.
Or the essential software is in a directory which is not in your PATH.
In any case, you need to be root.

berndbausch · 11-18-2015, 03:08 AM

Quote:

Originally Posted by Huamin

I done such command on server fine. But I still get same problem to telnet server on port 8000 on client machine.

Which command?
And what's the output?

pan64 · 11-18-2015, 03:25 AM

none of these commands (ss, netstat, lsof) will fix your issue, they are only used to check your config. They should be executed as root and please post the output exactly, do not need to explain/modify it, just post.

Huamin · 11-18-2015, 04:14 AM

Here are what I get
[root@hpi5 sbin]# ptables -S
bash: ptables: command not found
[root@hpi5 sbin]# ss -lntp | grep 8000
bash: ss: command not found
[root@hpi5 sbin]#
[root@hpi5 sbin]# lsof -i :8000
bash: lsof: command not found

pan64 · 11-18-2015, 04:17 AM

that is no ptables, but iptables. please try again and also the netstat command I requested

Huamin · 11-18-2015, 04:35 AM

[root@hpi5 sbin]# iptables -S
bash: iptables: command not found
[root@hpi5 sbin]# ss -lntp | grep 8000
bash: ss: command not found
[root@hpi5 sbin]#
[root@hpi5 sbin]# lsof -i :8000
bash: lsof: command not found
[root@hpi5 sbin]#
[root@hpi5 sbin]# netstat -a | grep 8000
[root@hpi5 sbin]#
[root@hpi5 sbin]#

pan64 · 11-18-2015, 06:16 AM

thanks, it looks like port 8000 is not in use at all. So you need to find out what should listen on that port and start that application.

berndbausch · 11-18-2015, 07:54 AM

Quote:

Originally Posted by Huamin

[root@hpi5 sbin]# iptables -S
bash: iptables: command not found
[root@hpi5 sbin]# ss -lntp | grep 8000
bash: ss: command not found
[root@hpi5 sbin]#
[root@hpi5 sbin]# lsof -i :8000
bash: lsof: command not found
[root@hpi5 sbin]#
[root@hpi5 sbin]# netstat -a | grep 8000
[root@hpi5 sbin]#
[root@hpi5 sbin]#

It's rare to find a system that has neither iptables nor lsof. Worrying, actually.
What distro and version is it?

Huamin · 11-18-2015, 08:14 AM

Please see this
[oracle@hpi5 ~]$ cat /etc/redhat-release
Red Hat Enterprise Linux Server release 5.11 (Tikanga)
[oracle@hpi5 ~]$

Thanks a lot.

pan64 · 11-18-2015, 08:32 AM

probably /sbin/iptables -S will work. Can you check it?

Habitual · 11-18-2015, 08:55 AM

Quote:

Originally Posted by Huamin

I've done such command on server fine. But I still get same problem to telnet server on port 8000 on client machine.

If there is nothing listening on the server machine, using the telnet client program won't connect to it.

Quote:

Originally Posted by Huamin

As I cannot run the Oracle Form from Server machine, on client machine, while Oracle form does work through Port 8000. This is why I try the way to telnet through port 8000.

Start Oracle Form Server on the server that has it installed.
Verify it is running on the server using

Code:

netstat -a | grep 8000

Connect to the server port:8000 from the client machine.

berndbausch · 11-18-2015, 09:13 AM

Quote:

Originally Posted by Habitual

If there is nothing listening on the client machine, using the telnet client program won't connect to it.

You mean server.

Habitual · 11-18-2015, 09:36 AM

Quote:

Originally Posted by berndbausch

You mean server.

Corrected. Thank you!

Huamin · 11-18-2015, 07:10 PM

I still get
[root@hpi5 oracle]# /sbin/iptables
iptables v1.3.5: no command specified
Try `iptables -h' or 'iptables --help' for more information.
[root@hpi5 oracle]#

how to enable 8000 port on the server?

berndbausch · 11-18-2015, 07:42 PM

Quote:

Originally Posted by Huamin

I still get
[root@hpi5 oracle]# /sbin/iptables
iptables v1.3.5: no command specified
Try `iptables -h' or 'iptables --help' for more information.
[root@hpi5 oracle]#

how to enable 8000 port on the server?

There are many comments in this thread. Please read them. Let me help you a little while Hungary is asleep:

Quote:

Originally Posted by pan64

probably /sbin/iptables -S will work. Can you check it?

Quote:

Originally Posted by pan64

thanks, it looks like port 8000 is not in use at all. So you need to find out what should listen on that port and start that application.

Quote:

Originally Posted by pan64

none of these commands (ss, netstat, lsof) will fix your issue, they are only used to check your config. They should be executed as root and please post the output exactly, do not need to explain/modify it, just post.

And this:

Quote:

Originally Posted by Habitual

Start Oracle Form Server on the server that has it installed.
Verify it is running on the server using

Code:

netstat -a | grep 8000

Connect to the server port:8000 from the client machine.

To summarize: There are at least two prerequisites to connect to a TCP/IP port on a server:

The firewall doesn't block the port. Check this with iptables -S or other firewall commands, depending on your distro version.
A process is listening on that port. You checked this with the netstat command and found that no process is listening.

Since #2 is missing, start that process. Perhaps Habitual's answer goes into the right direction.
But you will also have to check #1.

Most importantly, when you ask for help, please read and follow people's suggestions. I find it mildly insulting that we tell you to do certain things and you persist not listening to us.