The name of a computer is entirely arbitrary--the main user normally chooses a short word s/he likes. The domain name of the home network is also entirely arbitrary, unless you have a permanent connection in which case a domain name is registered to you. Try to invent something that does not exist yet--it could make your life easier once you have a permanent connection.
As for the DNS (domain name server, also called "named" = name daemon), RedHat 5.2 and 6.0 comes with DNS preinstalled as "caching-only" so it is easy to configure as such. You may also choose not to use local DNS at all--if your local DNS is looking up an "outside" server and can't find it, it can be a real show-stopper (the machine can appear to be hanged for up to a few minutes). To use local DNS, the "named" service must be enabled-- check this by running setup. To set up the caching-only DNS, fill up the appropriate boxes in netconf. E.g., I filled "nameserver 1" to my first machine on all computers (I entered the loopback address 127.0.0.1 on the machine xxx.xxx.xxx.1, and the proper xxx.xxx.xxx.1 address on all other machines).
No routes to other networks and hosts were required in my network, since I don't have other local networks. So I left this field blank.
Other than setting up the hardware correctly and filling up the info under netconf on each computer, as described above, I did not have to do anything on the standard RedHat to get my network working.
Reboot all computers one by one in any order (this is not necessary, but won't hurt you) and watch the boot messages (if they scroll too fast off screen, use <Shift><PgUp> to scroll up, or use dmesg from the command line to view them later). Did your cards configure correctly? Use the command route (as root) to see if the eth0 interface is running. Use the ping command to test the connections between individual machines. Try to telnet your local computer to see it the loopback-only (lo) interface works:
telnet name_of_the_machine_you_are_sitting_at
After a successful login, you can exit the telnet session by typing
exit
Finally, try to telnet another computer on your network:
telnet name_of_a_remote_machine
If this works on all machines, your eth0 network interface is set up.
After setting up your ppp and connecting to your Internet Service Provider (ISP), you will have another network interface (ppp0) and then will be able to telnet any machine in the world.
Here is a summary of the meaning of IP numbers.
The IP number (sometime called "IP address") is split into four groups of numbers separated by dots. E.g., 123.123.123.123 is a fromally-valid IP number. (All numbers here are shown in their decimal representations.) Within each group of numbers, the value may range from 0 to 255 (8 bits). The group of numbers from dot to dot is often referred to as an "octet" because it has 8 digits in its binary representation. The address contains a "network number" followed by "host number" (a host is an individual computer within a network). The network may be denoted by one, two, or three octets. The host is the trailing balance of the IP number (three, two, or one octet, respectively).
When the host number is filled with zeros (in all octets that denote the host), the resulting IP number is interpreted as referring to this host (therefore, the number is called "the network number"). When the host number is filled with 255 (in all the octets), the IP address is interpreted as all hosts on the network (and called "the broadcast address"). When the network number is filled with zeros (in all the octets that denote the network), it is interpreted as referring to this network. If the network number is filled with 255 (in all its octets), it refers to all networks.
Networks are divided into 6 classes. The most important are class A, B, and C.
Class A networks. Class A networks are networks with numbers between 1.0.0.0 and 127.0.0.0. The network number is contained in the first octet. The host number is contained in the trailing three octets. This division results in 127 big networks,
