DNS problem?

[Alan Curtis]

I am running a FreeBSD server behind a Linksys Wireless Access  
Point / Router (BEFW11S4). Its local address is 192.168.1.1. The  
Linksys is attached to a DSL modem.  In my /etc/rc.conf file I have
defaultrouter=192.168.1.1
which works most of the time. However occasionally, all network  
traffic freezes, I cannot login to the server using ssh and my  
mailing lists and websites do not function. If, at my server, I type  
"host someip.com" it reports 'no server can be found' or some similar  
message (I sorry, I didn't note down the exact message) - a reboot  
has fixed the problem.

I assume that the problem is that the server is unable to find a DNS  
server. Is that right?
  Do I have it right that I should point defaultrouter at the firewall?
How do I tell FreeBSD about other DNS servers to use if the firewall  
route fails?
Why does pointing defaultrouter at the filewall  fail?

Thanks

Alan