多路ADSL绑定，问题？？？

geniusjoy

有一条ADSL的专线，两条虚拟IP线。应该怎样绑定一个网关，还可以负载平行啊？
高手们请教教我。。。。。。。。。。。
谢谢~~~！！！

rainren

Load Balance Outgoing Traffic

http://www.openbsd.org/faq/pf/pools.html


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 keep state

The route-to option is used on traffic coming in on the internal interface to specify the outgoing network interfaces that traffic will be balanced across along with their respective gateways. Note that the route-to option must be present on each filter rule that traffic is to be balanced for. Return packets will be routed back to the same external interface that they exited (this is done by the ISPs) and will be routed back to the internal network normally.

To ensure that packets with a source address belonging to $ext_if1 are always routed to $ext_gw1 (and similarly for $ext_if2 and $ext_gw2), the following two lines should be included in the ruleset:

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

Finally, NAT can also be used on each outgoing interface:

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

A complete example that load balances outgoing traffic might look something like this:

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"

#  nat outgoing connections on each internet interface
nat on $ext_if1 from $lan_net to any -> ($ext_if1)
nat on $ext_if2 from $lan_net to any -> ($ext_if2)

#  default deny
block in  from any to any
block out from any to any

#  pass all outgoing packets on internal interface
pass out on $int_if from any to $lan_net
#  pass in quick any packets destined for the gateway itself
pass in quick on $int_if from $lan_net to $int_if
#  load balance outgoing tcp traffic from internal network.
pass in on $int_if route-to \
    { ($ext_if1 $ext_gw1), ($ext_if2 $ext_gw2) } round-robin \
    proto tcp from $lan_net to any flags S/SA modulate state
#  load balance outgoing udp and icmp traffic from internal network
pass in on $int_if route-to \
    { ($ext_if1 $ext_gw1), ($ext_if2 $ext_gw2) } round-robin \
    proto { udp, icmp } from $lan_net to any keep state

#  general "pass out" rules for external interfaces
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

#  route packets from any IPs on $ext_if1 to $ext_gw1 and the same for
#  $ext_if2 and $ext_gw2
pass out on $ext_if1 route-to ($ext_if2 $ext_gw2) from $ext_if2 to any
pass out on $ext_if2 route-to ($ext_if1 $ext_gw1) from $ext_if1 to any