I installed Fedora for the first time today, at work on
a mostly windows LAN - (aside from one BSD server). everything
was working fine using dhcp. (browsing, download all ok :-)

As the installation didn't ask for a host name, I tried to set it
myself. Not knowing about the GUIs then, I simply ran
hostname tiger
at the command line. Following this, I rebooted the machine and
now eth0 fails (hangs til it times out), and I suspect this
is due to dhclient also failing...
mysteriously, I do not see the hostname "tiger" anywhere.

I then found the gnome network config GUI and under the "DNS" tab
I have set the Hostname to tiger.company.domain.name
(is that the right format?)
but alas the damage appears to have been done somewhere and
eth0 still will not start (neither "ifup eth0" nor GUI activation nor reboot)
now that a hostname is present in /etc/sysconfig/network it complains
that the hostname is not in /etc/hosts too. but earlier today when it
worked fine, only the loopback line appeared in the hosts file..

help? can someone please tell me how to re-set it so eth0 and dhcp will work again?

thanks v.much, newbie.

The command hostname only sets the hostname temporary for the duration of the session. Next reboot it will be reset to what is written in the configuration files.

To set the hostname on a Red Hat edit /etc/sysconfig/network:
HOSTNAME=<hostname>

and
/etc/hosts:
<IP> <hostname>

ah thanks. should the host name within /etc/sysconfig/network include domain name ?
thanks again.

No it should be the same as you see on the console prompt.