About Layer 2 Generic Routing Encapsulation (L2GRE) Tunnels
L2GRE tunnels are used to route traffic from any remote device to a GigaVUE-H Series or GigaVUE-TA Series device over the internet. The device at the remote site encapsulates the filtered packets, adds a L2GRE encapsulation header, and routes it to the main office site. The encapsulation protocol is GRE and the delivery protocol is IP, so the encapsulation header consists of Ethernet + IP + GRE headers. The parameters of the encapsulated header are user-configurable, such as the IPv4 address of the IP interface on the destination GigaVUE device and the GRE key that identifies the source of the tunnel.
The encapsulated packet is sent out of the tool port, which is connected to the public network (the Internet). This packet is routed in the public network to reach the main office site. The packet is ingressed at the circuit port of the GigaVUE device at the main office. The received packet’s destination IP is checked against the IP configured for the circuit port. If they match, decapsulation is applied. The Ethernet + IP + GRE header is stripped and the remaining packet is sent to the tool port.
Refer to the following sections for details about the L2GRE tunnel termination:
| • | About L2GRE Tunnel Termination |
| • | L2GRE Tunnel Termination—Rules and Notes |
| • | Configure L2GRE Tunnel Termination |
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