Unable to telnet a Linux Box from a Windows 2000 Server

Unable to telnet a Linux Box from a Windows 2000 Server

Post by tzut » Sat, 20 Mar 2004 10:43:29



Hi guys!

I just setup a new Red HAt Linux 7.1 box at home and I created a small
network with a crossover cable to my Windows 2000 box. I have assigned
a private address to my Linux box, 172.25.25.25 and 172.25.25.26  for
my Win box.

I was able to ping both these machines, I was able to telnet my Win
machine but for whatever reason I cannot telnet the linux machine on
any port. I can telent the Linux machine from the linux terminal so
the telnet process is actually working. I know telnet is listening,
httpd is listening and some other port like 22 is open. I even scanned
the linux box and I saw the ports open.
I've tried PUTTY as well, didn't work. When using telnet from Windows,
the message returned was: Connecting to 172.25.25.25......  Could not
open a connection to host on port 23.. Connect failed.

The Windows box is connected to the inernet and has 2 NICs. No routing
service is working.
In short, the only communication between the two boxes is ping at this
moment.

Thanks for reading,
hopefully you can give me a hint..

Tavi

 
 
 

Unable to telnet a Linux Box from a Windows 2000 Server

Post by sean » Sat, 20 Mar 2004 11:18:56


Are you running a fireall, IIRC redhat 7.1 used IP chains, and was not
turned on by default.  Log into the server on the console and run:
"ipchains -nL" to see if there any rules in place.  (man ipchains)

Did you install the a telnet server, and if you did, did you activate it?


> Hi guys!

> I just setup a new Red HAt Linux 7.1 box at home and I created a small
> network with a crossover cable to my Windows 2000 box. I have assigned
> a private address to my Linux box, 172.25.25.25 and 172.25.25.26  for
> my Win box.

> I was able to ping both these machines, I was able to telnet my Win
> machine but for whatever reason I cannot telnet the linux machine on
> any port. I can telent the Linux machine from the linux terminal so
> the telnet process is actually working. I know telnet is listening,
> httpd is listening and some other port like 22 is open. I even scanned
> the linux box and I saw the ports open.
> I've tried PUTTY as well, didn't work. When using telnet from Windows,
> the message returned was: Connecting to 172.25.25.25......  Could not
> open a connection to host on port 23.. Connect failed.

> The Windows box is connected to the inernet and has 2 NICs. No routing
> service is working.
> In short, the only communication between the two boxes is ping at this
> moment.

> Thanks for reading,
> hopefully you can give me a hint..

> Tavi


 
 
 

Unable to telnet a Linux Box from a Windows 2000 Server

Post by Jeff Breitne » Sat, 20 Mar 2004 13:16:46



> Hi guys!

> I just setup a new Red HAt Linux 7.1 box at home and I created a small
> network with a crossover cable to my Windows 2000 box. I have assigned
> a private address to my Linux box, 172.25.25.25 and 172.25.25.26  for
> my Win box.

> I was able to ping both these machines, I was able to telnet my Win
> machine but for whatever reason I cannot telnet the linux machine on
> any port. I can telent the Linux machine from the linux terminal so
> the telnet process is actually working. I know telnet is listening,
> httpd is listening and some other port like 22 is open. I even scanned
> the linux box and I saw the ports open.
> I've tried PUTTY as well, didn't work. When using telnet from Windows,
> the message returned was: Connecting to 172.25.25.25......  Could not
> open a connection to host on port 23.. Connect failed.

Assuming your network is operating properly, there's a couple things you
need to look for within Red Hat.

First, this version of RH may have packet filtering enabled to stop
telnet access.  I believe you can easily test this theory by issuing the
command (as root) /etc/rc.d/init.d/ipchains off.  If it gives an
affirmative response that it turned it off, then you know you're not
hampered by any packet filtering for the next test.

Next, once we've determined that there's no packet filtering, open up a
terminal window and telnet to localhost.  If that fails, then your inetd
or xinetd super-server is not configured for telnet and/or you haven't
installed the telnet server rpm.  If you have installed the rpm, it will
write the appropriate entries into inetd or xinetd and all you need to
do is enable them and restart the super-server.

 
 
 

Unable to telnet a Linux Box from a Windows 2000 Server

Post by tzut » Mon, 22 Mar 2004 10:57:36




> > Hi guys!

> > I just setup a new Red HAt Linux 7.1 box at home and I created a small
> > network with a crossover cable to my Windows 2000 box. I have assigned
> > a private address to my Linux box, 172.25.25.25 and 172.25.25.26  for
> > my Win box.

> > I was able to ping both these machines, I was able to telnet my Win
> > machine but for whatever reason I cannot telnet the linux machine on
> > any port. I can telent the Linux machine from the linux terminal so
> > the telnet process is actually working. I know telnet is listening,
> > httpd is listening and some other port like 22 is open. I even scanned
> > the linux box and I saw the ports open.
> > I've tried PUTTY as well, didn't work. When using telnet from Windows,
> > the message returned was: Connecting to 172.25.25.25......  Could not
> > open a connection to host on port 23.. Connect failed.

> Assuming your network is operating properly, there's a couple things you
> need to look for within Red Hat.

> First, this version of RH may have packet filtering enabled to stop
> telnet access.  I believe you can easily test this theory by issuing the
> command (as root) /etc/rc.d/init.d/ipchains off.  If it gives an
> affirmative response that it turned it off, then you know you're not
> hampered by any packet filtering for the next test.

> Next, once we've determined that there's no packet filtering, open up a
> terminal window and telnet to localhost.  If that fails, then your inetd
> or xinetd super-server is not configured for telnet and/or you haven't
> installed the telnet server rpm.  If you have installed the rpm, it will
> write the appropriate entries into inetd or xinetd and all you need to
> do is enable them and restart the super-server.

Thanks guys,

actually the problem was that ipchains was filtering all the pors. I
thought ipchains should be a process and because I couldn't find any
process with this name running I assumed it was off. But it is
actually part of the kernel.
I only had to insert a rule to allow connections from my windows box.
Easy..