One of the kb suggested that udp 4500 traffic should be allow from end to end in order to establish a tunnel. If we enable the ESP as the transport mode, the default port is 4500 udp. What port does it use if the ssl as a transport mode? Still udp 4500?
ESP is for the data & you can change the port if you don't like the 4500 option. SSL transport uses the SSL protocol for transport, hence, as muttbarker said, port 443.
