deconfigure ssh2 to get telnet working again

[Antonio Gonzalez_4]

when I configure ssh2 server, telnet stop working. We now want to leave ssh and get back telnet working as before.
We don't know how ssh stops telnet, but now my system (5.1B C2) doesn't listen to port 23, but the services file is unchanged !!

any help ??

[Ralf Puchner]

have you checked /etc/inetd.conf?

The services-files is only a portname/portnumber converting mechanism.

[Antonio Gonzalez_4]

In fact the /etc/inetd.conf is also unchanged.
When you reboot the system, it doesn't listen to the port 23 anymore (#netstat -a)

thanks
antonio

[Ralf Puchner]

don't check the date or if a file was modified, post the inetd.conf line for telnet so we know what you have configured else it is a "guess".

If telnetd doesn't start at all, check the log files for error messages. Maybe ssh will eat up all free ports in the range of 23...

[Brad Wilke_1]

I see the same behavior on our machines (5.1B).

Mabye this is obvious to you already but I found that stopping the ssh2 daemon allows telnet to work again. The command is:

/sbin/init.d/sshd stop

The documentation seems to point to the EnforceSecureRutils parameter in the /etc/ssh2/ssh2_config file on the client machine. Even after setting this to "no" I found that telnet won't work when the ssh2d is running on the server side.

[Antonio Gonzalez_4]

Brad, we have already done this. Stopping sshd doesn't solve the telnet problem. Even we commented out the ssh start script in init.d and reboot. Of course the sshd deamon dont start but the telnet still fail.
---
There is not any telnet deamon running in my system. In fact, looking to a system (5.1B also) without ssh configured, where the telnet is working, you can`t see any telnetd process either.
---
I thought that this was something usual in the ssh world. I now see that something wrong is happening here. I'll post all the configuration files in a couple of days.

Thanks

[Ralf Puchner]

telnetd will be started by inetd if the inetd.conf contains a valid entry. The entry within inetd.conf also specifies if a tcp-wrapper will be used.

So a telnetd is only seen if a connection was established or started.

we are still waiting for the config files...

[Antonio Gonzalez_4]

Lets use 2 boxes: DB1 & AS2
DB1 - 5.1B without ssh2 "server" configured.
Telnet works. The telnetd starts when is needed by inetd.
This box can use ssh2 without problem.

AS2 - 5.1B with ssh2 "server" configured.
Telnet gives this error:
db1./u01/oracle> telnet as2
Trying 172.17.0.17...
telnet: Unable to connect to remote host: Connection refused
db1./u01/oracle>

We'd like to be able to use ssh2 "AND" telnet.
This is the case in DB1; both (ssh2 & telnet works).

As far as I know, telnet should accept connections in AS2:
- /etc/services seems to be OK
- /etc/inetd.conf same story
- netstat doesn't show up telnet as being "listened".
I can't post the sshd_config file until tomorrow; sorry.

I post a parcial snapshot of services & inetd.conf.

What I suspect is that the configuration od ssh2 server somehow is preventing telnet from accespting connections anymore.

Thanks for your help
regards
antonio

[Antonio Gonzalez_4]

I can now post the sshd2_config file of the system that doesn't accept telnets (AS2).

Any more ideas will be welcome.
Thanks
antonio