I have a temlnet problem -telnet 192.168.0.4 1004 failed.

At 192.168.0.2, "telnet 192.168.0.4" make connection successfully at port 23, however "telnet 192.168.0.4 1000" does not make connection at port 1000.

Please let me know how to solve this problem.

Thanks in advance.

Hi,

Is anything listening on port 1000 (or 1004, both are mentioned in your post)? If nothing is listening, you cannot connect to it.

If something is listening on either of those ports, please tell us a bit more (what is listening for example).

Hope this helps.

Allow traffic over port 1004.

Sorry the simple answer, but I have a hard time understanding your problem. You are giving to few informations.

Cheers

At first, you will have to change the port, or add the additional 1000-number port that the telnet server will listen to.
At the moment your telnet server is listening on 23 port only, which is the default. You can add another port on which the
server will listen to and you will be able to have telnet to listen on both ports 23 and 1000 if you like.

At first, you will have to install xinetd, if you do not already have it installed. Inetd (the older version), is highly insecure and I would not recommend its use. The following example is based on the xinetd package.

Assuming you are using Ubuntu, or a Debian like Distro, in the console type:

root# apt-get install xinetd

in order to install the package. Then, edit the /etc/services file and put an entry for your modified telnet server
like this:

mytelnet 1000/tcp # My Telnet server

Then, go to /etc/xinetd.d/ directory and create a file called mytelnet containing the following:

service mytelnet
{
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.telnetd
log_on_failure += USERID
disable = no
port = 1000
}

After that execute in the console:

root# /etc/init.d/xinetd restart

to restart xinetd and all should be in order. I would also suggest, if you were using inetd BEFORE installing xinetd, to go
to the /etc/inetd.conf file and commnent-out the line that looks like this:

telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/in.telnetd

To comment it out simply put a '#' at the beginning of the line, making it look like this:

#telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/in.telnetd

Then go to the /etc/xinetd.d/ directory and in there create a file called telnet containing
the following:

service telnet
{
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.telnetd
log_on_failure += USERID
disable = no
}

and again restart xinetd with

root# /etc/init.d/xinetd restart

Now, verify that your telnet servers are running with the command:

root# netstat -a | grep telnet

it should return something like this:

tcp 0 0 *:mytelnet *:* LISTEN
tcp 0 0 *:telnet *:* LISTEN

meaning that all your telnet servers are running.

Now try to telnet to port 1000 from another machine. In order to disable one of the telnet
services, simply go to the corresponding file in /etc/xinetd.d/ and change the line
disable to 'yes'.

Hope that I have helped

-Fk

To add something to my previous post. If in the file /etc/services you see another service using port 1000, then choose another number for mytelnet. You will know if another service is using port 1000 if you see a line in the file looking
like this:

anotherService 1000/tcp # Another service comment or

anotherService 1000/udp # Another service comment

If you change the port number in here, then you must change it also in the /etc/xinetd.d/mytelnet file by
changing the 'port' section to the other number that you put in the /etc/services file in the mytelnet line.

-Fk

Filip_Kv/

Thanks a lot!

I followd your kid and detailed guide, and connected successfully!