I guess what I'm looking for is a ProxyPass directive that allows me to specify the source IP to use when connecting to the remote server.
So perhaps a table of what we desire:
ProxyVirtualHostIP ProxySourceIP DestinationServer A C E B D F
I guess this can't be done with mod_proxy but you could configure your routing table like this:
ip route add E dev eth0 src C ip route add F dev eth0 src D
At least this is how it works on Linux provided that eth0 holds C and D. Note that this applies to *all* connections to E and F, not only those originating from Apache.
Hope this helps.
cg.
