PPP allowed you to use the -nat
to enable packet forwarding between machines on the local network. NATD has to be used to accomplish this using DHCP.
Add the following to a custom kernel configuration file:
options IPFIREWALL options IPDIVERT options IPFIREWALL_DEFAULT_TO_ACCEPT options IPFIREWALL_VERBOSE
Rebuild and install the new kernel.
Add the following to /etc/rc.conf and then reboot:
gateway_enable="YES" firewall_enable="YES" firewall_type="OPEN" natd_enable="YES" natd_interface="ed0" natd_flags=""
This is a "wide-open" firewall but should machines on the internal network to access the internet.
This produces the following default ruleset:
# ipfw list 00050 divert 8668 ip from any to any via ed0 00100 allow ip from any to any via lo0 00200 deny ip from any to 127.0.0.0/8 00300 deny ip from 127.0.0.0/8 to any 65000 allow ip from any to any 65535 allow ip from any to any