Very Computer

We have a problem at our school, and our teachers have no time to work on it
so i'm left with no choice, but to try to do something myself, but since I
really have no clue what to do I ask if any you linux.net.gurus could help.

We have a Linux machine on the net, to which we can telnet from our
computers at school and from where we can ftp for example and all works
fine. But the problem is that that Linux machine cannot be telnetted from
outside of our domain. Ping works fine however. We have an another Linux
machine on our domain that can be telnetted from outside of our domain, but
me and my teachers have no access to that machine so that won't do any help.
And I was told from our network provider that the problem with the machine
could of its network configuration. So any help would be appreciated.  
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 * ATP/Linux 1.42 * can't rain all the time

  Christopher Neufeld,
  In a message on 4 January, wrote :

CN> Newsgroup: comp.os.linux.admin
CN> Organization: University of Toronto - Dept. of Physics
CN>


CN> >We have a Linux machine on the net, to which we can telnet from our
CN> >computers at school and from where we can ftp for example and all works
CN> >fine. But the problem is that that Linux machine cannot be telnetted fro
CN> >outside of our domain.
CN> >
CN>    I'll bet you don't have a gateway off the local network. Run the
CN> "route" command.

Kernel routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
localhost       *               255.255.255.255 UH    0      0        0 lo
193.199.20.0    *               255.255.255.0   U     0      0     1023 eth0
default         193.199.20.30   *               UG    0      0      192 eth0

CN>    Find the name of a gateway to the outside world. Make a static routing
CN> entry pointing to it, then mark it as the default gateway.

This is what i have in rc.net

route add 193.199.20.0
route add default gw 193.199.20.30

If I'm correct what you suggested is already done?  
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 * ATP/Linux 1.42 * can't rain all the time

   I'll bet you don't have a gateway off the local network. Run the
"route" command. Here's what I get when I run it:

Kernel routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
mcl4.gw.utoront *               255.255.255.255 UH    0      0    11839 eth0
helios.physics. irides.physics. 255.255.255.255 UGHDM 0      0     7281 eth0
pncd10.physics. irides.physics. 255.255.255.255 UGHDM 0      0   1005151 eth0
pncd13.physics. irides.physics. 255.255.255.255 UGHDM 0      0   1003632 eth0
pncd12.physics. irides.physics. 255.255.255.255 UGHDM 0      0    95137 eth0
pncd11.physics. irides.physics. 255.255.255.255 UGHDM 0      0    41559 eth0
128.100.75.0    *               255.255.255.0   U     0      0   154753 eth0
127.0.0.0       *               255.0.0.0       U     0      0   1210946 lo
default         mcl4.gw.utoront *               UG    0      0   675346 eth0

That last line is what was necessary for me to get access off the local
net. Well, the last and the first, I suppose. In the /etc/rc.d/rc.inet1 I
have the following lines:

/sbin/route add -host "mcl4-physics-ether.gw"
/sbin/route add default gw "mcl4-physics-ether.gw" metric 10

   Find the name of a gateway to the outside world. Make a static routing
entry pointing to it, then mark it as the default gateway.

--

 Home page:  http://caliban.physics.utoronto.ca/neufeld/Intro.html
 "Don't edit reality for the sake of simplicity"

   Looks that way, yes. I'm cross-posting this to the networking group,
the good people there should be able to help more than I can.  I'm no
expert on this, though I did have the problem you mention, and my fix was
to get the gateway installed (and kill routed, which was merrily deleting
the gateway entry from my routing table).
   I wonder about the mask on your "localhost" entry, it's different from
mine. You also don't have a static link to the gateway, but I don't think
that's a problem.
   Oh, you say you can't telnet in from off the local domain. Can you
telnet out of the local domain? Or FTP? Does telnet work with IP numbers
but not with names?

--

 Home page:  http://caliban.physics.utoronto.ca/neufeld/Intro.html
 "Don't edit reality for the sake of simplicity"

: We have a problem at our school, and our teachers have no time to work on it
: so i'm left with no choice, but to try to do something myself, but since I
: really have no clue what to do I ask if any you linux.net.gurus could help.

: We have a Linux machine on the net, to which we can telnet from our
: computers at school and from where we can ftp for example and all works
: fine. But the problem is that that Linux machine cannot be telnetted from
: outside of our domain. Ping works fine however. We have an another Linux
: machine on our domain that can be telnetted from outside of our domain, but
: me and my teachers have no access to that machine so that won't do any help.
: And I was told from our network provider that the problem with the machine
: could of its network configuration. So any help would be appreciated.  

Is it possible that you are using TCP wrappers and have telnet disabled from
anywhere but your local network? Check /etc/hosts.deny and /etc/hosts.allow
to see if they are restricting access to your machine.

--
  Gary Maltzen

  Compuserve 74166,1524

CN>    Oh, you say you can't telnet in from off the local domain. Can you
CN> telnet out of the local domain? Or FTP? Does telnet work with IP numbers
CN> but not with names?

        Yes I can use telnet, ftp, lynx, netscape... perfectly, from my
computer. Names work fine too. But from outside telnet doesn't work with
either names or IP numbers.

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 * ATP/Linux 1.42 * can't rain all the time