If a network card is to be configured, you have to decide on the IP-address, FQDN and possible aliases for use in the /etc/hosts file. The syntax is:
<IP address> myhost.mydomain.org aliases
You should made sure that the IP-address is in the private network IP-address range. Valid ranges are:
Class Networks A 10.0.0.0 B 172.16.0.0 through 172.31.0.0 C 192.168.0.0 through 192.168.255.0
A valid IP address could be 192.168.1.1. A valid FQDN for this IP could be www.linuxfromscratch.org.
If you aren't going to use a network card, you still need to come up with a FQDN. This is necessary for certain programs to operate correctly.
If a network card is not going to be configured, create the /etc/hosts file by running:
cat > /etc/hosts << "EOF" # Begin /etc/hosts (no network card version) 127.0.0.1 www.mydomain.com <value of HOSTNAME> localhost # End /etc/hosts (no network card version) EOF
If a network card is to be configured, create the /etc/hosts file by running:
cat > /etc/hosts << "EOF" # Begin /etc/hosts (network card version) 127.0.0.1 localhost.localdomain localhost 192.168.1.1 www.mydomain.org <value of HOSTNAME> # End /etc/hosts (network card version) EOF
Of course, the 192.168.1.1 and www.mydomain.org have to be changed to your liking (or requirements if assigned an IP-address by a network/system administrator and this machine is planned to be connected to an existing network).