16.7. Tunnel

You can find the Tunnel Settings at Interfaces → Assign → Tunnel.

Tunnels do not need an underlying interface. They are defined by their source IP Address that must be defined in the system.

We support the following Tunnel modes:

  • GRE
  • SIT

Assign to new Interface is an option shown when you create a new Tunnel and it will automatically assign the Interfaces as described in Assign Interfaces.

16.7.1. Interface Tunnel Settings

Any other tunnel settings must be defined on the corresponding Interface page.

A tunnel always has an outer IP Type and an inner IP Type. The outer IP Type is IPv4 or IPv6 depending, on the tunnel type there is no choice. This sets the sender and destination of the Tunnel to an IPv4 or IPv6 Address.

Local Public IP Address is the sender IP Address and it is an Interface or Virtual IP Address of VT AIR or when host is selected any IP you enter.

Remote Public IP Address is the destination IP Address of the remote endpoint

Tunnel Address Version is depending on the Tunnel Type IPv4 or IPv6 and represents the inner IP Type

Local Tunnel IP Address is the local tunnel IP Address and the corresponding subnet mask. Make sure that the remote endpoint has a different IP Address in the same subnet.

GRE Keepalive for GRE respond to keepalive packages for IPv4.

GRE Responder Only This will only answer the packages and it does not have any influence on the tunnel status. The tunnel is always up in VT AIR. Disable this option to also actively send GRE Keepalive Packets and set the interface to down if no response is received.

GRE Interval The interval to send GRE keepalive packets to the remote address.

GRE Retries Retries before the Tunnel is set to down when no GRE keepalive is answered.