lan_net="10.7.0.0/16"
corp_lan="10.0.0.0/8"
int_if="fxp0"

ext_if1="em0"
ext_if2="em1"
ext_if3="em2"

ext_gw1=WAN_IP1
ext_gw2=DSL_IP1
ext_gw3=DSL_IP2

nat on $ext_if1 from $lan_net to any -> ($ext_if1)
nat on $ext_if2 from $lan_net to any -> ($ext_if2)
nat on $ext_if3 from $lan_net to any -> ($ext_if3)

block in from any to any
block out from any to any
pass out on $int_if from any to $lan_net

pass in quick on $int_if from $lan_net to $int_if

pass in on $int_if route-to { ($ext_if1 $ext_gw1), ($ext_if2 $ext_gw2), ($ext_if3 $ext_gw3)} round-rob
in proto tcp from $lan_net to any flags S/SA modulate state
pass in on $int_if route-to { ($ext_if1 $ext_gw1), ($ext_if2 $ext_gw2), ($ext_if3 $ext_gw3) } round-ro
bin proto { udp, icmp } from $lan_net to any keep state

pass out on $ext_if1 proto tcp from any to any flags S/SA modulate state
pass out on $ext_if1 proto { udp, icmp} from any to any keep state
pass out on $ext_if2 proto tcp from any to any flags S/SA modulate state
pass out on $ext_if2 proto { udp, icmp} from any to any keep state
pass out on $ext_if3 proto tcp from any to any flags S/SA modulate state
pass out on $ext_if3 proto { udp, icmp} from any to any keep state

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

pass out on $ext_if2 route-to ($ext_if1 $ext_gw1) from $ext_if1 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_if1 to any
pass out on $ext_if3 route-to ($ext_if2 $ext_gw2) from $ext_if2 to any