topic Re: About telnet in Operating System - Linux

About telnet

juno2 — Thu, 28 Aug 2003 05:24:14 GMT

I have setting up my RH8 Linux server , I have started the telnet service , now it can telnet to local host , but it don't accept other machine to telnet into it , ( ping is OK ) , can suggest what is problem in my setting ? thx.

Re: About telnet

Claudio Cilloni — Thu, 28 Aug 2003 05:43:08 GMT

try disabling the firewall:

# service iptables stop

hth
Claudio

Re: About telnet

Stuart Browne — Thu, 28 Aug 2003 05:43:49 GMT

What error message do you get when you try to telnet in from the other machine?

Are you usnig TCP wrappers (what are the contents of /etc/hosts.allow and /etc/hosts.deny) ?

What answer did you give to the Firewall questions during the installation?

What do these two commands return:

ipchains -nvL
iptables -nvL

These commands show the contents of your firewall (if one is in use). If they show information, you'll either need to open a hole in them (in which case, paste the reults here so we can give you the right command), or to disable them completely (use either 'service iptables stop' or 'service ipchains stop', depending on which gave output.

If it just hangs for a few minutes when telnetting in, it's probably due to a reverse-lookup on the IP. Try adding the IP of the other machine to the /etc/hosts file of the server, or by correctly configuring a DNS server (either your own if it's a private network, or a remote for external 'real world' addresses).

Details Juno. You should know by now that we need more details.

Re: About telnet

juno2 — Thu, 28 Aug 2003 05:46:36 GMT

I never setup the firewall , just use the default setting .

Re: About telnet

juno2 — Thu, 28 Aug 2003 05:52:09 GMT

the error message is
telnet: connect to address 168.6.85.4: Connection refused

Re: About telnet

Stuart Browne — Thu, 28 Aug 2003 06:30:49 GMT

The default is for 'medium firewall'.

And the error message definately points to firewall.

Do those two commands, and show us the output.

Re: About telnet

juno2 — Thu, 28 Aug 2003 06:30:50 GMT

I have another problem , the server can accept rcp from other host , even I have update /etc/securetty and /root/.rhosts , what service need to start and want setting should be modify in my system ? Thanks in advance.

Re: About telnet

juno2 — Thu, 28 Aug 2003 07:01:37 GMT

Thx , I have disable the firewall , it is ok now .

Re: About telnet

juno2 — Thu, 28 Aug 2003 07:21:04 GMT

how can i permenently disable the firewall ? thx

Re: About telnet

Alexander Chuzhoy — Thu, 28 Aug 2003 07:44:16 GMT

Hey Juno2!
How about assigning points to all the people who helped you?
best regards!

Re: About telnet

Steven E. Protter — Thu, 28 Aug 2003 09:53:51 GMT

To permanently disable the firewall,
mv /etc/rc3.d/S08iptables /etc/rc3.d/s08iptables

making it a little s preserves if for after you get attacked and want to bring it back.

bad idea. firewalls are GOOD.

rename the softlink that starts it or null out the config file. Firewalls are good though, you might just want to add a line to iptables(I don't think ipchains was in RH8)

/etc/sysconfig/iptables

-A INPUT -i eth0 -p tcp -m tcp --dport 22 -j okay

Same basic idea in ipchains. enable telnet.

Also make sure the service is enabled in /etc/xinetd.d/telnet file

disable=no

service xinetd restart

SEP
Will work for points or money.

Re: About telnet

Stuart Browne — Thu, 28 Aug 2003 22:21:05 GMT

Incidentally, the easier/cleaner way to disable the firewall is to use:

chkconfig iptables off

It does all the messing around with the /etc/rc.d/* files for you.