Telnet, FTP ... sometimes work, sometimes they don't!

Telnet, FTP ... sometimes work, sometimes they don't!

Post by Marc Koschewsk » Fri, 15 Dec 2000 23:21:09



Hi all,

I have a weird problem. I have a Linux box with Mandrake 7.2 which I use a
home and work. When I am at work I can Telnet to that box by IP
192.168.0.250 from a client 192.168.0.1 (WinNT 4.0 Svr). When I am at home
I cannot connect to the Linux box from a client (WinNT 4.0 Wkst) although
it has the same IP address as one of our in-house servers has
(192.168.0.1). The only difference is the workgroup name which is GRUPEHJF
at work and TESTLOCAL at home. Anyone has an idea or knows any settings I
may not have set correctly or services I didn't start ... I use middle
security level on Mandrake ....

Help is really appreciated ...

Thanks, Marc

--

Mit freundlichen Gruessen

Marc Koschewski
Programmierung

Freund & Co. GmbH
Mollenkotten 195
D-42279 Wuppertal

Fon: +49 202 / 2 62 78 - 5
Fax: +49 202 / 2 62 78 - 70
WWW: http://www.freund-co.com/

 
 
 

Telnet, FTP ... sometimes work, sometimes they don't!

Post by Jeff » Sat, 16 Dec 2000 07:25:00



Quote:> Hi all,

> I have a weird problem. I have a Linux box with Mandrake 7.2 which I use a
> home and work. When I am at work I can Telnet to that box by IP
> 192.168.0.250 from a client 192.168.0.1 (WinNT 4.0 Svr). When I am at home
> I cannot connect to the Linux box from a client (WinNT 4.0 Wkst) although

192.168.* is an IP to be used by internal networks.  You cannot telnet
192.168.* from anywhere other than your own internal network.  It must have
a valid IP.

 
 
 

Telnet, FTP ... sometimes work, sometimes they don't!

Post by Jens » Fri, 15 Dec 2000 22:46:24






>> Hi all,

>> I have a weird problem. I have a Linux box with Mandrake 7.2 which I
>> use a home and work. When I am at work I can Telnet to that box by IP
>> 192.168.0.250 from a client 192.168.0.1 (WinNT 4.0 Svr). When I am at
>> home
>> I cannot connect to the Linux box from a client (WinNT 4.0 Wkst)
>> although

> 192.168.* is an IP to be used by internal networks.  You cannot telnet
> 192.168.* from anywhere other than your own internal network.  It must
> have
> a valid IP.

Of course you _can_ connect to other networks with any IP address
(including the 192.168.* ones). You just _cannot_ connect to or over the
_internet_. 192.168.* addresses are by convention not routed over the
internet, but in (a) private network(s) you can do whatever you want.

The problem why Marc can't connect to his Linux box from home is probably
that the IP address he uses is already used in the internal network at
work. So of course there can be no packages routed back to his NT Wkst at
home. What he has to do is get a valid IP address at home, that can be
routed from his network at work.

If he wants to connect over the internet, he does indeed need valid IP
addresses for both machines, so that both machines find each other over
the internet. If he just connects through a separate modem connection,
cable modem or whatever directly into his company, he has to talk to his
network administrator to get the right IP address for his machine at
home.

Jens

 
 
 

Telnet, FTP ... sometimes work, sometimes they don't!

Post by Marc Koschewsk » Sat, 16 Dec 2000 20:34:55







> >> Hi all,

> >> I have a weird problem. I have a Linux box with Mandrake 7.2 which I
> >> use a home and work. When I am at work I can Telnet to that box by IP
> >> 192.168.0.250 from a client 192.168.0.1 (WinNT 4.0 Svr). When I am at
> >> home
> >> I cannot connect to the Linux box from a client (WinNT 4.0 Wkst)
> >> although

> > 192.168.* is an IP to be used by internal networks.  You cannot telnet
> > 192.168.* from anywhere other than your own internal network.  It must
> > have
> > a valid IP.

> Of course you _can_ connect to other networks with any IP address
> (including the 192.168.* ones). You just _cannot_ connect to or over the
> _internet_. 192.168.* addresses are by convention not routed over the
> internet, but in (a) private network(s) you can do whatever you want.

> The problem why Marc can't connect to his Linux box from home is probably
> that the IP address he uses is already used in the internal network at
> work. So of course there can be no packages routed back to his NT Wkst at
> home. What he has to do is get a valid IP address at home, that can be
> routed from his network at work.

> If he wants to connect over the internet, he does indeed need valid IP
> addresses for both machines, so that both machines find each other over
> the internet. If he just connects through a separate modem connection,
> cable modem or whatever directly into his company, he has to talk to his
> network administrator to get the right IP address for his machine at
> home.

> Jens

Guys, I carry my laptop from my work office to my home office. NO
CONNECTION OVER THE INTERNET!!!!!!!!!! I take my laptop home!!! The
networks and IP addresses are ***absolutely*** the same but the fact that
the workgroups are GRUPPEHJF at work and TESTLOCAL at home!

--

Mit freundlichen Gruessen

Marc Koschewski
Programmierung

Freund & Co. GmbH
Mollenkotten 195
D-42279 Wuppertal

Fon: +49 202 / 2 62 78 - 5
Fax: +49 202 / 2 62 78 - 70
WWW: http://www.freund-co.com/

 
 
 

Telnet, FTP ... sometimes work, sometimes they don't!

Post by Jens » Sat, 16 Dec 2000 14:51:50




>> >> I have a weird problem. I have a Linux box with Mandrake 7.2 which I
>> >> use a home and work. When I am at work I can Telnet to that box by
>> >> IP
>> >> 192.168.0.250 from a client 192.168.0.1 (WinNT 4.0 Svr). When I am
>> >> at
>> >> home I cannot connect to the Linux box from a client (WinNT 4.0
>> >> Wkst) although

>> > 192.168.* is an IP to be used by internal networks.  You cannot
>> > telnet
>> > 192.168.* from anywhere other than your own internal network.  It
>> > must
>> > have a valid IP.

>> Of course you _can_ connect to other networks with any IP address
>> (including the 192.168.* ones). You just _cannot_ connect to or over
>> the
>> _internet_. 192.168.* addresses are by convention not routed over the
>> internet, but in (a) private network(s) you can do whatever you want.

>> The problem why Marc can't connect to his Linux box from home is
>> probably that the IP address he uses is already used in the internal
>> network at work. So of course there can be no packages routed back to
>> his NT Wkst at home. What he has to do is get a valid IP address at
>> home, that can be routed from his network at work.

>> If he wants to connect over the internet, he does indeed need valid IP
>> addresses for both machines, so that both machines find each other over
>> the internet. If he just connects through a separate modem connection,
>> cable modem or whatever directly into his company, he has to talk to
>> his network administrator to get the right IP address for his machine
>> at home.

>> Jens

> Guys, I carry my laptop from my work office to my home office. NO
> CONNECTION OVER THE INTERNET!!!!!!!!!! I take my laptop home!!! The
> networks and IP addresses are ***absolutely*** the same but the fact
> that  the workgroups are GRUPPEHJF at work and TESTLOCAL at home!

I wonder how your laptop switches from NT Srv to NT Wkst while you carry
it home, but ok.

How should your Linux machine know that your laptop is all of a sudden
reached at another network? The Linux machine assumes that your laptop is
still in your work office. So it just sends its packages into the local
(work) network.

What you need is a _different_ IP address for your laptop when you are at
home. This IP address must not be in the same subnet as your Linux box
(that is, you cannot take a 192.168.0.* address). (Sorry, I don't know
right now, how to set that up with NT. I think it was something about
different hardware profiles, but I'm not sure.)

Then you have to make sure, that all routing informations in your
networks are set up correctly, so that the Linux box can find the way to
your laptop at home. I don't know how you connect to your work office
from home, but I will assume here a router connection (e.g. with an ISDN
router). Then you could set up something like this:

  +--------------+
  |laptop at home|
  | 192.168.1.1  |
  +------+-------+
         |                   home network
     ----+----------------+----------
                          |
                   +------+-------+
                   | 192.168.1.2  |
                   |    router    |
                   | 192.168.2.1  |
                   +------+-------+
                          |
                          / phone line
                          |
                   +------+-------+
                   | 192.168.2.1  |
                   |    router    |
                   | 192.168.0.2  |
                   +------+-------+
                          |           work network
     ----+----------------+--------+-------
         |                         |
  +------+-------+          +------+-------+
  |Linux at work |          |laptop at work|
  | 192.168.0.250|          | 192.168.0.1  |
  +--------------+          +--------------+

This is a standard way to set up an router connection. You can check your
network connections with tools like 'ping', 'traceroute' ('tracert' on
Windows NT) or 'ifconfig' ('ipconfig' on NT).

All this has nothing to do with the Windows workgroups. These workgroups
are only relevant for browsing in the Windows "Network Environment".

Setting up a scenario like the above one is a standard task in TCP/IP
networking. The basics of TCP/IP are pretty simple, but too long to write
in the newsgroup. It would be probably a good idea to go into the next
library and grab a book about networking. Once you get the idea about
subnetting and routing, this will solve 95% of your network problems in
the future, and this one too.

Hope I could help you a little bit.

Jens

 
 
 

Telnet, FTP ... sometimes work, sometimes they don't!

Post by Michael Erskin » Sun, 17 Dec 2000 03:23:46



> Hi all,

> I have a weird problem. I have a Linux box with Mandrake 7.2 which I use a
> home and work. When I am at work I can Telnet to that box by IP
> 192.168.0.250 from a client 192.168.0.1 (WinNT 4.0 Svr). When I am at home
> I cannot connect to the Linux box from a client (WinNT 4.0 Wkst) although
> it has the same IP address as one of our in-house servers has
> (192.168.0.1). The only difference is the workgroup name which is GRUPEHJF
> at work and TESTLOCAL at home. Anyone has an idea or knows any settings I
> may not have set correctly or services I didn't start ... I use middle
> security level on Mandrake ....

You have worse problems than connectivity.  I expect others will clue you.

--
  Yesterday is ashes, tomorrow wood, today, well, today you are likely
                        to be eaten by a grue.
        Anon -- Native American, slightly modified by M. Erskine

 
 
 

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