I have a home network setup with one computer acting as a gateway using ppp and demand dial and IP Masq. I know that if i go with highspeed cable connection I will need to put in another nic card, but what will I need to use instead of ppp to create the connection a pick up the address from my ISP? I always have a little trouble moving to these new technology. It took my mind a little while to grasp ethernet instead of dumb terminals with serial connections too.
Thanks
Linda

It's just ethernet, really. 99% of cable ISPs assign IPs out dynamically, which means using DHCP. There are several different DHCP clients out there - which one you'll have depends on which distro you run.

Cable generally makes things much easier for us Linux folks, compared to dial-up.

The cable connection with the cable modem is always on. You simply configure that interface to use DHCP, and it will be assigned an IP address, netmask, and the nameserver addresses will be automatically written to /etc/resolve.conf by the dhcpd client.

One other thing to do, which is probably done already is to configure your firewall.
If you have a Cable/DSL modem, then you configure the interface the same way, but it is to the Router connection instead. The router is both a DHCP client with the cable modem, and a DHCP server for your network. A NAT router will also provide the masquerading, which as a byproduct will function as an outer firewall.

For example, using Mandrake, there is a GW module that you use to configure NAT; using SuSE Security&Users->Firewall is where you'll find it.

If you don't have a cable/dsl router, and you have other computers, you will need to configure network sharing. Different distro's have different configuration dialogs for this, but it probably is a part of the firewall setup, because it is performed by the netfilter kernel module. (The netfilter module is the Linux firewall module that the iptables command configures.) On some other distro's you will need to manually configure your firewall and masquerading.