Generic routing encapsulation (GRE) provides a private, secure path for transporting packets through an otherwise public network by encapsulating (or tunneling) the packets. GRE tunneling is accomplished through tunnel endpoints that encapsulate or de-encapsulate traffic.

Foundation Topics > CCNP ISCW Exam Guide: GRE Tunneling The GRE Tunnel Information window is the first configuration window of the Secure GRE Wizard. There are two sets of IP addresses that are applied to the GRE tunnel interface—the tunnel source and destination (at the top of the window) represent the GRE IP header (shown in Figure 14-3 ). ENCOR Training » IPSec and GRE 2. Create the GRE tunnel interfaces. 3. Add the tunnel subnet to the routing process so that it exchanges routing updates across that interface. 4. Add GRE traffic to the crypto access list, so that IPsec encrypts the GRE tunnel traffic. An example of configuring GRE Tunnel is shown below: interface Tunnel0 ip address How to Configure and Verify GRE - ExamCollection The GRE is defined by the RFC 2784. The GRE was developed as the tunneling tool which is meant to carry any of the OSI layer 3 protocol over the IP network. Lets us see how to configure and verify the Generic Routing Encapsulation. The GRE will create the private point to … Packet Tracer – Troubleshooting GRE - ICT Community

The GRE tunnel would operate as an overlay network but behave like a point-to-point serial link in many ways. The IP addresses on the two tunnel end point interfaces would be configured from a single subnet, as if they were directly connected. Figure 12-4 GRE Tunnel Interfaces We summarize GRE tunnel configuration steps here:

Generic Routing Encapsulation (GRE), defined by RFC 2784, is a simple IP packet encapsulation protocol. A GRE tunnel is used when IP packets need to be sent from one network to another, without being parsed or treated like IP packets by any intervening routers. For example, in Mobile IP, a mobile node registers with a Home Agent.

GRE over IPsec (Cisco VPN) – Fortinet GURU

- GRE / DTLS (phase II) tunnel is established between the SonicWall UTM appliance and the SonicPoint-N device(s) to carry management and data traffic. Scenario: Discovering and managing SonicPoint-Ns using the GRE Tunneling with DHCP addressing method. Note: The configuration illustrated below is based on the above network diagram. GRE Tunnels - Network Direction To achieve this, we’re going to use a GRE tunnel. Each edge router is configured with a Virtual Tunnel Interface (VTI). This is quite different to some other VPNs you may have seen (like the ASA), which use policies to tunnel traffic instead of using interfaces.The VTI is configured with a destination address.