Hi, we would like to use stunnel in transpartent mode. Therefore we already applied iptable changes as mentioned in the man page : Re-write address to appear as if wrapped daemon is connecting from the SSL client machine instead of the machine running stunnel. This option is currently available in: remote mode (I<connect> option) on Linux >=2.6.28 Linux >=2.6.28 requires the following setup for iptables and routing (possibly in /etc/rc.local or equivalent file): iptables -t mangle -N DIVERT iptables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT iptables -t mangle -A DIVERT -j MARK --set-mark 1 iptables -t mangle -A DIVERT -j ACCEPT ip rule add fwmark 1 lookup 100 ip route add local 0.0.0.0/0 dev lo table 100 However the connection to the services cannot be established and we run into a timeout. 2015.02.09 10:00:03 LOG7[6658:139940568909760]: ldaps-in accepted FD=12 from xxxxxx:51018 2015.02.09 10:00:03 LOG7[6658:139940568905472]: ldaps-in started 2015.02.09 10:00:03 LOG7[6658:139940568905472]: FD 12 in non-blocking mode 2015.02.09 10:00:03 LOG7[6658:139940568905472]: Waiting for a libwrap process 2015.02.09 10:00:03 LOG7[6658:139940568905472]: Acquired libwrap process #0 2015.02.09 10:00:03 LOG7[6658:139940568905472]: Releasing libwrap process #0 2015.02.09 10:00:03 LOG7[6658:139940568905472]: Released libwrap process #0 2015.02.09 10:00:03 LOG7[6658:139940568905472]: ldaps-in permitted by libwrap from xxxxxxx:51018 2015.02.09 10:00:03 LOG5[6658:139940568905472]: ldaps-in accepted connection from xxxxxxx:51018 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): before/accept initialization 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 read client hello A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 write server hello A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 write certificate A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 write server done A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 flush data 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 read client key exchange A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 read finished A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 write change cipher spec A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 write finished A 2015.02.09 10:00:03 LOG7[6658:139940568905472]: SSL state (accept): SSLv3 flush data 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 1 items in the session cache 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 client connects (SSL_connect()) 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 client connects that finished 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 client renegotiations requested 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 1 server connects (SSL_accept()) 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 1 server connects that finished 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 server renegotiations requested 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 session cache hits 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 external session cache hits 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 session cache misses 2015.02.09 10:00:03 LOG7[6658:139940568905472]: 0 session cache timeouts 2015.02.09 10:00:03 LOG6[6658:139940568905472]: SSL accepted: new session negotiated 2015.02.09 10:00:03 LOG6[6658:139940568905472]: Negotiated ciphers: AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 2015.02.09 10:00:03 LOG7[6658:139940568905472]: FD 13 in non-blocking mode 2015.02.09 10:00:03 LOG6[6658:139940568905472]: local_bind succeeded on the original port 2015.02.09 10:00:03 LOG6[6658:139940568905472]: connect_blocking: connecting 127.0.0.1:10389 2015.02.09 10:00:03 LOG7[6658:139940568905472]: connect_blocking: s_poll_wait 127.0.0.1:10389: waiting 10 seconds 2015.02.09 10:00:13 LOG3[6658:139940568905472]: connect_blocking: s_poll_wait 127.0.0.1:10389: timeout 2015.02.09 10:00:13 LOG5[6658:139940568905472]: Connection reset: 0 bytes sent to SSL, 0 bytes sent to socket 2015.02.09 10:00:13 LOG7[6658:139940568905472]: ldaps-in finished (0 left) Any idea why the timeout is occuring? Best regards, Shushant