Generic Routing Encapsulation

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Generic Routing Encapsulation

(networking, protocol)
(GRE) A protocol which allows an arbitrary network protocol A to be transmitted over any other arbitrary network protocol B, by encapsulating the packets of A within GRE packets, which in turn are contained within packets of B.

Defined in RFC 1701 and RFC 1702 (GRE over IP).
References in periodicals archive ?
In a GRE tunnel environment, the PoP routers are only one hop away from each other regardless of how many hops the transport network is taking, which greatly simplifies troubleshooting.
Highlight features include 4K flow entries and GRE tunnel support in hardware," said by Mr.
Encrypted multicast over generic routing encapsulation (GRE) using GRE tunnel protection capabilities on the IPSec VPN Shared Port Adapter Module with IOS 12.
APCON's IntellaTap-VE communicates to standard Linux KVM hypervisors to easily identify and enable taps of virtual machine traffic, set traffic filters, follow migration events and forward traffic over unidirectional GRE tunnels to monitoring systems.
The only way to do that is establish a tunnel from one end to the other, and GRE tunnels solve this problem.
Together, they designed a managed virtual private network (VPN) with redundant GRE tunnels that used open shortest path first routing between critical hub sites to ensure the automatic re-routing of traffic over the alternate provider link in the event of network congestion or failure on the primary path.
The new Fidelis XPS IP Tunnel cyber decoder provides full inspection of sessions running over 6to4, 6over4, Teredo, and GRE tunnels.
Because GRE tunnels are transparently carried over an IP network, no new cabling changes or VLANs are required for the wired network.
A number of different technologies are available on the Catalyst 6500 Series Switches to enable each step such as: NAC (Network Admission Control) and Identity Based Networking Services for access control, VRF-lite (Virtual Route Forwarding), GRE Tunnels (Generic Route Encapsulation) and MPLS (Multi-Protocol Label Switching) for path isolation, as well as, integrated services modules for policy enforcement.
The line card provides dedicated resources to support the establishment of tunnels and LNS termination for L2TP in addition to GRE tunnels, IPSec tunnels and IP multicast.