NB3000-Line-Hd User Manual 4.2
5.6.4. GRE
The Generic Routing Encapsulation (GRE) is a tunneling protocol that can encapsulate a wide
variety of network layer protocols inside virtual point-to-point links over IP. GRE is defined in
RFC 1701, 1702 and 2784. It does not provide encryption nor authorization but can be used
on an address-basis on top of other VPN techniques (such as IPsec) for tunneling purposes.
The following parameters are required for setting up a tunnel:
Parameter
GRE Configuration
Peer address
The IP address of the remote peer
Interface
The device type for this tunnel
Local tunnel address
The local IP address of the tunnel
Local tunnel netmask
The local subnet mask of the tunnel
Remote network
The remote network address of the tunnel
Remote netmask
The remote subnet mask of the tunnel
In general, the local tunnel address/netmask should not conflict with any other interface
addresses. The remote network/netmask will result in an additional route entry in order to
control which packets should be encapsulated and transferred over the tunnel.
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