Is there a NAMESERVER env variable?

[johnwebb]

I have a Redhat Linux box that acts as a gatway and dhcp server for a small network. The external address and dns info is assigned via dhcp from the provider. Is there a env variable that can be used in the dhcpd.conf file for the doman-name-server option so that any nameserver changes by the provider will be passed along to the inside clients? Or is this not possible because a dncp restart would be required?

Thanks
johnwebb