Mac OS 10.2.3 has a NIC configuration option called "Using DHCP with manual IP address."

What does this do? What are the implications for NAT? What would be the equivalent setup on Redhat 8?

RedHat's configuration tool offers only dynamic (dhcp, bootp, dailup) or static. With static, you also specify a gateway. For dhcp, the only way I can reach the Internet through the router is to let it assign the router as the primary DNS server although the LAN works. My recollection for earlier versions of RedHat is that you could choose DHCP and also specify the gateway.

I am one confused newbie.

I know on RH 7.3, you can add this line:
GATEWAY=[gateway ip]
in your /etc/sysconfig/network file. Or you could just let DHCP do it for you. I would assume that RH 8 is the same... let me know things are NOT this way under RH8.

Adding a GATEWAY= line did not help.

I still could not get to the Internet unless I allow RH to set my route as the primary DNS server. It's a long story, but I discovered on a fresh installation on another machine that this problem did not occur. It may be a DHCP option regarding hostnames that I selected during installation.

I dont understand what you mean by 'allow RH to set my route as the primary DNS server'. IP routing, including the default gateway, never rely on name resolution unless you set something like this in /etc/sysconfig/network:
GATEWAY=gatewayip.somedomain.com
If your gateway is set in this fashion, (which is a bad idea, because your DNS server may be on a different subnet that your host cannot get to without a default gateway, which your host will not be able to resolve because it has no gateway,etc.). If you have your gateway set as a name, make sure you map the name to an IP in /etc/hosts. Hope this helps...

That should have read "set my router as the primary DNS server."

The RedHat network device configuration tool has a panel for each NIC that allows you to choose DHCP with options to set a DHCP hostname and to "automatically obtain DNS information from provider." If I check the latter, the my router address appears on the DNS panel (separate panel) as the primary DNS server. If I recall, this also happens no matter what on the DHCP panel if I do not enter a hostname on the DNS panel.

There was no GATEWAY= line in /etc/sysconfig/network. I could not tell any difference when I entered the IP address of the router and rebooted. I have a simple LAN with everything on 192.168.1.x.

I am in the process of reinstalling RH, making sure to set the hostname during the installation.

Thanks for the input.

Reinstalling will definitely help things out, but it would have been much faster and easier just to configure yourself a hostname by specifying it in /etc/sysconfig/network by adding the line:
HOSTNAME=computername or:
HOSTNAME=computername.domainname
Probably would have used the first entry, assuming DHCP is assigning a DNS suffix to your DHCP clients.
BTW, how are things in Cary? (my old stomping grounds ;-)

I am giving up on Linux on this machine - a Dell Precision Workstation 530 with dual Xeons and a Quadro2 EX. It shipped with RH 7.3 pre-installed and that worked. I've had nothing but trouble since going to RH 8.0. Since those problems have little to do with this thread, I'll spare you the details but I am about to order Win2K Pro to put on the machine. No meanfull support from either Dell or RedHat. I have five Dells in the house and about seven retail RedHats. I'll be damned if I will have any more of either.

Why don't you send email if you want to talk about Cary?