...
network --device eth0 --bootproto static --ip 10.196.7.13 --netmask 255.255.252.0 --gateway 10.196.5.1 --nameser
ver 10.196.5.131,10.195.1.118 --hostname dell-13.vsaa.lv
network --device eth1 --onboot no --bootproto dhcp --hostname dell-%servernumber%.vsaa.lv
...
%post
mkdir /install
cd /install
wget http://<ip>/rh-postinstall
chmod 755 /install/rh-postinstall
/install/rh-postinstall
# before, in the postinstall script, hostname was correctly set to dell-13.
# now it is localhost/localdomain