How do I set the source address on a multi-homed host?

[Daniela]

On Saturday 12 February 2005 16:06, Volker Kindermann wrote:
> Hi Daniela,
>
> > Yes, this happens when I connect from my machine (which functions as a
> > router with NAT to allow the other LAN machines connect to the internet)
> > to another LAN machine. When the router establishes a connection to
> > another point in the intranet, the source address used is my official IP,
> > and not 10.0.0.1, which is the intranet IP of the router.
>
> please post the output of the following commands:
>
> ifconfig -a

[Showing only relevant entries. My official IP is replaced with x.x.x.x]
rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet6 fe80::202:44ff:fe66:bf4%rl0 prefixlen 64 scopeid 0x1 
        inet x.x.x.x netmask 0xffffff00 broadcast x.x.x.255
        ether 00:02:44:66:0b:f4
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active
rl1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet6 fe80::20a:cdff:fe00:c076%rl1 prefixlen 64 scopeid 0x2 
        inet 10.0.0.1 netmask 0xff000000 broadcast 10.255.255.255
        ether 00:0a:cd:00:c0:76
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active

> netstat -nr

Destination        Gateway            Flags    Refs      Use  Netif Expire
default            x.x.x.1            UGSc        0   340313    rl0
10                 link#2             UC          2        0    rl1
10.0.0.3           00:0d:61:17:fc:30  UHLW        1      444    rl1    903
10.255.255.255     ff:ff:ff:ff:ff:ff  UHLWb       0     2453    rl1
x.x.x/24           link#1             UC          2        0    rl0
x.x.x.1            00:d0:88:01:03:f5  UHLW        1        0    rl0    623
x.x.x.x            127.0.0.1          UGHS        2     3458    lo0
x.x.x.255          ff:ff:ff:ff:ff:ff  UHLWb       1     2464    rl0
127.0.0.1          127.0.0.1          UH          1     5540    lo0