pass out on $ext_if route-to ($ext_if2 $ext_gw2) from $ext_if2 \
   to any
pass out on $ext_if route-to ($ext_if3 $ext_gw3) from $ext_if3 \
   to any
pass out on $ext_if2 route-to ($ext_if1 $ext_gw1) from $ext_if \
   to any
pass out on $ext_if2 route-to ($ext_if3 $ext_gw3) from $ext_if3 \
   to any
pass out on $ext_if3 route-to ($ext_if1 $ext_gw1) from $ext_if \
   to any
pass out on $ext_if3 route-to ($ext_if2 $ext_gw2) from $ext_if2 \
   to any