Establishment of virtual private networks (VPN)
- OpenVPN 2.0: UDP/1194 and TCP/1194.
- IPv6 Tunnel Broker Service: protocol IP 41 inbound and outbound.
- IPsec NAT-Traversal UDP/4500
- Cisco IPSec VPN over TCP: TCP/10000 outbound only.
- PPTP VPN: Protocol IP 47 (GRE) inbound and outbound.