Amigo eu uso aqui no meu provedor essas regras ai para Bancos e a de Load Balance até 6 modens;
ve se te ajuda:
Bancos ( Bradesco,Real, BMG, BB, Caixa, HSBC, Banestes, Itau, Unibanco, F2B)
chain=prerouting action=add-src-to-address-list src-address=!162.126.14.2 dst-address=200.155.88.0/24
address-list=BBradesco address-list-timeout=1h in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=200.208.0.0/16
in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=200.251.0.0/16
in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=170.66.0.0/16
in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=200.201.0.0/16
in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=200.152.0.0/16
in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=200.165.0.0/16
in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=200.196.0.0/16
in-interface=ether1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no dst-address=200.230.0.0/16
in-interface=ether1
chain=prerouting action=add-src-to-address-list src-address=!162.126.14.2 dst-address=200.198.182.0/24
address-list=BBradesco address-list-timeout=1h in-interface=ether1
Regra para 6 modens
chain=prerouting action=mark-connection new-connection-mark=MMod1 passthrough=yes connection-state=new
in-interface=ether1 nth=5,0
chain=prerouting action=mark-routing new-routing-mark=MRot1 passthrough=no in-interface=ether1 connection-mark=MMod1
chain=prerouting action=mark-connection new-connection-mark=MMod2 passthrough=yes connection-state=new
in-interface=ether1 nth=5,1
chain=prerouting action=mark-routing new-routing-mark=MRot2 passthrough=no in-interface=ether1 connection-mark=MMod2
chain=prerouting action=mark-connection new-connection-mark=MMod3 passthrough=yes connection-state=new
in-interface=ether1 nth=5,2
chain=prerouting action=mark-routing new-routing-mark=MRot3 passthrough=no in-interface=ether1 connection-mark=MMod3
chain=prerouting action=mark-connection new-connection-mark=MMod4 passthrough=yes connection-state=new
in-interface=ether1 nth=5,3
chain=prerouting action=mark-routing new-routing-mark=MRot4 passthrough=no in-interface=ether1 connection-mark=MMod4
chain=prerouting action=mark-connection new-connection-mark=MMod5 passthrough=yes connection-state=new
in-interface=ether1 nth=5,4
chain=prerouting action=mark-routing new-routing-mark=MRot5 passthrough=no in-interface=ether1 connection-mark=MMod5
chain=prerouting action=mark-connection new-connection-mark=MMod6 passthrough=yes connection-state=new
in-interface=ether1 nth=5,5
chain=prerouting action=mark-routing new-routing-mark=MRot6 passthrough=no in-interface=ether1 connection-mark=MMod6
OBS: Lembrando que a sua MRot* vc determina lá no IP>Routes
Forte Abraço!!!!