pls help on 3 interfaces

[Julian Elischer]

Lin Zhao wrote:
> hi all, wish my english is enough :-)
> my freebsd has 3 interfaces, like this,
> 
>      ----                               ----switch1
>          |         ----------  fxp0    |
>          |        |          |---------
> internal |--------|freebsd71 |
>          |    rl0 |          |---------
>          |         ----------  fxp1    |
>      ----                               ----switch2

first set your routingtable so that teh 'special' addresses
go via switch2, then set up NAT as follows:

like this:

      ----                               ----switch1
          |         ----------  fxp0    |
          |        |   NAT1(*)|---------
internal |--------|freebsd71 |
          |    rl0 |      NAT2|---------
          |         ----------  fxp1    |
      ----                               ----switch2

(*) If you want, NAT1 may be left out if you use routable
addresses on your internal network.

The reason for the NAT is to make sure that outgoing packets
have a source address that will make the return packets come back 
through switch2, otherwise, even if you have a route
making the outgoing packets go via switch2, the return packets
will still comeback via switch1.


> 
> we're in the internal and want to visit outside
> we use fxp0 for default outside address and it works well
> but for some reason, i want to use fxp1 for some special outside address
> how can i do for it?
> thanks a lot.
> 
> 
> Lin Zhao
> SCGY,USTC,PRC
> 
> 
> _______________________________________________
> freebsd-ipfw at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-ipfw
> To unsubscribe, send any mail to "freebsd-ipfw-unsubscribe at freebsd.org"