looking at manual page for rc.conf

[Jeffry Killen]

I am looking at the manual page for rc.conf and am wondering
how I would specify default router address when using DHCP?

I don't see any further explicit elucidations beyond the text quoted  
below.

text from man page:

It is possible	to bring up an interface with DHCP by adding ``DHCP''  
to the ifconfig_<interface> variable.
For instance, to initialize the ed0 device via DHCP,	it is possible to  
use something like:
  ifconfig_ed0="DHCP"

actually, I have
  ifconfig_em0="DHCP"
Is the router address something that DHCP will figure out?
This interface will be for connection to internet via DSL modem
ISP is CenturyLink.

or alternately, suppose I want to assign a static address to interface
that would connect to internet via DSL modem.
  ifconfig_em0="inet 192.168.0.4 netmask 255.255.255.0"
When the router is at 192.168.0.1, how would this be specified.
I have also looked at ifconfig(8) and have found anything.
I have also had the kernel complain via a shell script set to
run in

I am also concerned about setting up tcp wrappers with inetd
to forestal possible attempts to access via telnet, ssh, ftp and
even MySql server (as I have seen frequently when I had static
ip address service). This I have done when I did have static ip
service. But with fire wall in DSL modem and DHCP configuration
is it useful and advantageous?