Question
Is it possible to configure the transparent proxy to use the client's address as source address in a connection? (I.e. the remote server sees the address of the client, and not of the firewall.)
Answer
Yes, the TPROXY patch makes both server-side and client-side transparency possible. Check the Forge Address checkbox for the router used in the service.
Additional information / References
See the Service parameters section in the Zorp services section of the Zorp Administrator's Guide at
http://www.balabit.com/dl/html/zorp-admin-guide.html/bk01-toc.html#zorp_services