Before revision: Common tunneling protocols IP in IP ( Protocol 4): IP in IPv4/IPv6 SIT/IPv6 ( Protocol 41): IPv6 in IPv4/IPv6 GRE ( Protocol 47): Generic Routing Encapsulation OpenVPN (UDP port 1194) SSTP (TCP port 443): Secure Socket Tunneling Protocol IPSec ( Protocol 50 and 51): Internet Protocol Security L2TP (UDP port 1701): Layer 2 Tunneling Protocol L2TPv3 ( Protocol 115): Layer 2 Tunneling Protocol version 3 VXLAN (UDP port 4789): Virtual Extensible Local Area Network.
After revision: Common tunneling protocols IP in IP ( IP protocol 4): IP in IPv4/IPv6 SIT/IPv6 ( IP protocol 41): IPv6 in IPv4/IPv6 GRE ( IP protocol 47): Generic Routing Encapsulation OpenVPN (UDP port 1194) SSTP (TCP port 443): Secure Socket Tunneling IP protocols IPSec ( IP protocol 50 and 51): Internet Protocol Security L2TP (UDP port 1701): Layer 2 Tunneling Protocol L2TPv3 ( Protocol 115): Layer 2 Tunneling Protocol version 3 VXLAN (UDP port 4789): Virtual Extensible Local Area Network.