The situation is as follows: I have a LAN which is connected to the
internet through a adsl-router (10.0.0.138) which also runs the DNS and
DHCP server for my LAN. Furthermore I have a server (10.0.0.155, RedHat
8.0) which runs an Apache server and several other services for LAN and
Internet users. This all works fine.

Since a short while we have the possibillity of a free telephone
connection between our office and a home user. At this moment the home
user has to dial-in at an normal ISP and has to pay per time. So now we
want to have this user to dial-in into our LAN to reduce costs. So we
did set-up a modem and mgetty at our server (10.0.0.155). And indeed,
the home-user (10.0.0.190) is able to call-in and make a connection as a
terminal. In fact he can reach any service running at the server
(10.0.0.155) including our website, ftp etc.

But now the problem: the home user (10.0.0.190) is unable to reach the
internet. In fact is he unable to ping any other box on the LAN, so
including the internet-router.

What we would like to obtain is:
OR the already mentioned above working stuff extended so that the home
user (10.0.0.190) also can use the internet
OR kinda pipeline from the home-user (10.0.0.190) to the
internet-router(10.0.0.138) through our server(10.0.0.155).

Does anybody have a clue in which direction I should search?

Thanks in advance,
Richard