DNS server: gateway_enable option in rc.conf?

[satellites at inorbit.com]

 Hello list,

I have a little confusion about a box I'm working on which will serve as a gateway  and DNS server.  

I am entering in the appropriate bind entries into the master files but my question is:

should I omit the gateway_enable option in the /etc/rc.conf file if I am already establishing those routes 
via the zone files?

In other words, I have a two-interface FreeBSD box, with interfaces dc0 and dc1.  Both of those interfaces have appropriate entries
establishing routes as 10.0.0.1 and 10.10.0.1 respectively.  

Many thanks for the pointers.  

Regards