I have two computers. One is a newer box running Win98 which I primarily use. The second is an older box running RedHat 7.1.
I already have the RedHat box setup as a DHCP server to a local network (my Win 98 box) and to IP Masq (It dials up using an analog modem). The problem is that I need to be able to make the RedHat box dial up and hang up on command from my Win98 box over the local network (The RedHat box is headless, no monitor or keyboard). Also, I am currently trying to configure the RedHat box to be a Samba server which means a lot of tweaking to get it how I want it. The switching of my monitor and keyboard is driving me nuts.
In order to play with Samba and command the box to dial and hang up, I want to set up a Telnet server on RedHat. I want to make it only run on the internal net and not on the dial up, security and all that. How would I go about doing this, or is there a better method?
I realize that diald can dial on net activity, but I also need to hangup at will, not time out. I have an external modem, so simply switching off the modem works well. After I switch it off and back on though, will Diald be able to dial up on more activity without having to mess with it?

To only make things appear on the internal network you want to set your self up a firewall on your ppp interfaces, and use any available directives for your programs to tell them only to listen on your ethernet interfaces (Samba for example has the 'interfaces' option in smb.conf).

As for dialing and disconnecting, I started by using diald but got anoyed when it decicded to make random 3 day phone calls, so moved to Masqdialer (C-mserver). This way you get a nice dial and hangup button on your Windows/Mac/Linux/justAboutAnything box that connects via your linux Masq box to the web allowing you to bring the ppp interface up and down at will on the remote box. Have a look at http://cpwright.com/mserver/

cheers

Jamie...

To set the telnet daemon to only allow connections from the inside you could use tcp wrappers.

In your inetd.conf file you should have a line like:
telnet stream tcp nowait root /usr/sbin/tcpd in.telnetd

Then you should set your hosts.deny to either
ALL:ALL
or
in.telnetd:ALL

and the hosts.allow file should have something like:
in.telnetd:192.168.1.2

That is assuming you are using inetd, if you are using xinetd then the file /etc/xinetd.d/telnet should look something like this:

service telnet
{
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.telnetd
log_on_failure += USERID
only_from = 192.168.1.2
}

But you could also use firewall rules to only allow internal access like jharris mentioned.

I have telnet up and running, visible only from the internal network. I use wvdial to dial in and it dials up fine. When I log out of the telnet connection though, the dial up closes too!! Why is wvdial and pppd connected to that login? is there anyway to dissociate it so that I can close the telnet connection?

I never used a modem in linux so I don't know what the wvdial script does. But you could try running it with the nohup command. It should keep it running even if you log out.