Биллинговая система Nodeny

Address pools can be used in combination with the route-to filter option to load balance two or more Internet connections when a proper multi-path routing protocol (like BGP4) is unavailable. By using route-to with a round-robin address pool, outbound connections can be evenly distributed among multiple outbound paths.
One additional piece of information that's needed to do this is the IP address of the adjacent router on each Internet connection. This is fed to the route-to option to control the destination of outgoing packets.

The following example balances outgoing traffic across two Internet connections:

lan_net = "192.168.0.0/24"
int_if  = "dc0"
ext_if1 = "fxp0"
ext_if2 = "fxp1"
ext_gw1 = "68.146.224.1"
ext_gw2 = "142.59.76.1"

pass in on $int_if route-to \
   { ($ext_if1 $ext_gw1), ($ext_if2 $ext_gw2) } round-robin \
   from $lan_net to any

И не забываем про  sticky-address

а как балансит? по сессиям? по пакетам? процентное соотношение можно указать?

Без sticky-address пакетно, с ним посессионно.

Я так понимаю нужно делать так?

lan_net = "192.168.0.0/24"
int_if  = "dc0"
ext_if1 = "fxp0"
ext_if2 = "fxp1"
ext_gw1 = "68.146.224.1"
ext_gw2 = "142.59.76.1"

pass in on $int_if route-to \
   { ($ext_if1 $ext_gw1), ($ext_if2 $ext_gw2) } round-robin sticky-address \
   from $lan_net to any

И еще вопрос как должны выглядеть правила для балансировки с опцией probability ? В инете очень мало примеров с этой опцией в основном раунд-робин