A transparent TCP proxy device intercepts TCP connection requests received from a TCP client and destined for a TCP server as if acting as the TCP server in a handshake with the TCP client. Only after completing the handshake with the TCP client, the transparent TCP proxy participates in a handshake with the TCP server as if acting as the TCP client. After the handshake with the TCP server is complete, the transparent TCP proxy intercepts and translates subsequent TCP packets received from the TCP client and destined for the TCP server into a form expected by the TCP server including updating an acknowledgement number and TCP checksum; and intercepts and translates subsequent TCP packets received from the TCP server and destined for the TCP client into a form expected by the TCP client including updating an acknowledgement number and TCP checksum.