There are a couple of problems if networking is configured with DHCP,
using the dhcpcd daemon.
1. Installer does not set DHCP_HOSTNAME in the ifcfg-eth0
This prevents dynamic dns working, as the hostname is not included with
the request. If the user specifies a hostname during installation then
that hostname should be used for the DHCP_HOSTNAME.
2. The DHCP_ARGS should include a -D option if the local domainname is
not set.
3. The DHCP_ARGS should include a -H option if the local hostname is not
set.
