Using mangle table to change source address, how?

[Mark Atwood]

I have an interface eth1, with an IP address 192.168.23.100

I've configured eth1 to have a subinterface eth1:1, and
have given that subinterface an IP address 172.23.1.3.

There is a host on the segment that this interface is connected to
with an IP address of 172.23.1.2.

If I send packets to that host 172.23.1.2, the packets from me have a
source address of 192.168.23.100, not 172.23.1.3!

Can I use the mangle table to rewrite the source address?  If so,
what is the iptable command line?

Or is there an easier way?

-- 
Mark Atwood   | Well done is better than well said.
mra@pobox.com | 
http://www.pobox.com/~mra