RHEL6 NetworkManager and /etc/dhclient-eth0.conf is being ignored

Issue

• Desktop systems use DHCP to get their IP address and set a DNS record. Use short hostnames on the clients ("abc" for example), but the DHCP server expects the full hostname to be returned for the DNS record to be set correctly.

To send the correct host name earlier the following setting was used

 /etc/dhclient-eth0.conf:

send host-name "abc.desktop.com";

This then populates the NetworkManager configuration file /var/run/nm-dhclient-eth0.conf with:

# Created by NetworkManager
# Merged from /etc/dhclient-eth0.conf

send host-name "abc.desktop.com";

However, this is no longer working since the application of errata RHBA-2011:1632-2. NetworkManager appears to ignore the contents of /etc/dhclient-eth0.conf. After applying the errata /var/run/nm-dhclient-eth0.conf contains:

# Created by NetworkManager
# Merged from /etc/dhclient-eth0.conf

send host-name "abc";

This results in the DNS record eventually being lost as the host name being sent is not correct.