The following is a list of the common VPN connection types, and the relevant ports, and protocols, that generally need to be open on the firewall for VPN traffic to flow through.
PPTP
| Protocol | Port |
| TCP | 1723 |
| GRE (Proto 47) | N/A |
SSTP
| Protocol | Port |
| TCP | 443 |
L2TP
| Protocol | Port |
| UDP | 1701 |
IPSec
| Protocol | Port | Description |
| UDP | 500 | IKE |
| UDP | 4500 | NAT-Traversal |
| ESP (Proto 50) | N/A | ESP |
| AH (Proto 51) | N/A | AH |
L2TP with IPSec
| Protocol | Port | Description |
| UDP | 1701 | L2TP |
| UDP | 500 | IPSec |
| UDP | 4500 | IPSEC – NAT Traversal |
OpenVPN
| Protocol | Port | Description |
| UDP | 1194 | Default Protocol |
| TCP | 1194 | Alternate Protocol |
IKEv2
| Protocol | Port | Description |
| UDP | 500 | IPSec IKEv2 |
| UDP | 4500 | NAT Traversal |
