From looking at the code, it appears that validate source is failing just because of the rp_filter. Do you have rp_filter set to nonzero? If so, it may do what you want just by setting that to 0:
sysctl -w net.ipv4.conf.all.rp_filter=0 +-DLS - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html