test# cat /etc/rc.conf
network_interfaces="lo0 ng0"
ifconfig_ng0="inet 10.0.0.1 10.0.0.2 netmask 255.255.255.0"

test# cat /etc/start_if.ng0 ! x21
ngctl mkpeer mn0: cisco x21 downstream
ngctl name mn0:x21 mn0hdlc
ngctl mkpeer mn0hdlc: iface inet inet

test# cat /etc/start_if.ng0 ! g703 unframed
ngctl config mn0: line e1u
ngctl mkpeer mn0: cisco unframed downstream
ngctl name mn0:unframed mn0hdlc
ngctl mkpeer mn0hdlc: iface inet inet

test# cat /etc/start_if.ng0 ! g703 framed
ngctl mkpeer mn0: cisco ts1-4 downstream
ngctl name mn0:ts1-4 mn0hdlc
ngctl mkpeer mn0hdlc: iface inet inet