TCP/IP networking with dynamic addresses

I have a Linux network which requires either fixed IP addresses or for one of the PCs to act as a name server. Since I am on a cable connection via a modem with dynamic addressing, neither of these are possible.

IP masquerading enables me to use one PC as a gateway that receives a dynamic address from my cable provider. A second ethernet card has a fixed address on an internal network with a router that allows other PCs with fixed addresses to communicate with each other as well as the internet.

All I had to do was to change a setting in /etc/sysconfig/sysctl
IP_FORWARD="yes"
and adding the following line to /etc/rc.d/rc.local
echo 7 > /proc/sys/net/ipv4/ip-dynaddr
(see SuSE Linux 8.2 Administration Guide, p.445 5th Edition.)

Firewall settings must also be such that a local network is permitted.