Hi there, I tried the same thing on an older machine running an old kernel and Centos 7 (Linux 3.10.0-862.3.3.el7.x86_64 #1 SMP Fri Jun 15 04:15:27 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux). I have the same RTMP handshaking problem. I read some more about the handshaking process, and it appears no other port is opened, machines just exchange specific chunks on the 1935 port. So... It looks like I have failed configuring correctly iptables or redsocks2. # Generated by iptables-save v1.4.21 on Thu Jun 25 19:05:27 2020 *mangle :PREROUTING ACCEPT [227900:207210144] :INPUT ACCEPT [227900:207210144] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [201078:31493812] :POSTROUTING ACCEPT [201078:31493812] COMMIT # Completed on Thu Jun 25 19:05:27 2020 # Generated by iptables-save v1.4.21 on Thu Jun 25 19:05:27 2020 *filter :INPUT ACCEPT [227900:207210144] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [201078:31493812] COMMIT # Completed on Thu Jun 25 19:05:27 2020 # Generated by iptables-save v1.4.21 on Thu Jun 25 19:05:27 2020 *nat :PREROUTING ACCEPT [6:864] :INPUT ACCEPT [6:864] :OUTPUT ACCEPT [372:24174] :POSTROUTING ACCEPT [9298:559734] :REDSOCKS - [0:0] -A PREROUTING -p tcp -m tcp --dport 443 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 1935 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 80 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 21 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 11371 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 9418 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 9418 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 6380 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 1080 -j REDSOCKS -A PREROUTING -p tcp -m tcp --dport 1935 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 443 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 1935 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 80 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 21 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 11371 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 9418 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 6380 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 443 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 80 -j REDSOCKS -A OUTPUT -p tcp -m tcp --dport 1935 -j REDSOCKS -A REDSOCKS -d 0.0.0.0/8 -j RETURN -A REDSOCKS -d 10.0.0.0/8 -j RETURN -A REDSOCKS -d 127.0.0.0/8 -j RETURN -A REDSOCKS -d 169.254.0.0/16 -j RETURN -A REDSOCKS -d 172.16.0.0/12 -j RETURN -A REDSOCKS -d 192.168.1.0/24 -j RETURN -A REDSOCKS -d 192.168.31.0/24 -j RETURN -A REDSOCKS -d 224.0.0.0/4 -j RETURN -A REDSOCKS -d 240.0.0.0/4 -j RETURN -A REDSOCKS -p tcp -j REDIRECT --to-ports 12345 -A REDSOCKS -d 0.0.0.0/8 -j RETURN -A REDSOCKS -d 10.0.0.0/8 -j RETURN -A REDSOCKS -d 127.0.0.0/8 -j RETURN -A REDSOCKS -d 169.254.0.0/16 -j RETURN -A REDSOCKS -d 172.16.0.0/12 -j RETURN -A REDSOCKS -d 192.168.0.0/16 -j RETURN -A REDSOCKS -d 224.0.0.0/4 -j RETURN -A REDSOCKS -d 240.0.0.0/4 -j RETURN -A REDSOCKS -p tcp -j REDIRECT --to-ports 12345 COMMIT # Completed on Thu Jun 25 19:05:27 2020
