How Does the GRE Protocol Work?

Generic Routing Protocol is a sophisticated tunneling protocol evolved by Cisco Systems as a solution to offer fast forwarding and routing of packets across the network. The technology uses a hop by hop VPN (VPLS) construction to connect two networks. Unlike IP networking where there is a single virtual IP address for every computer on a network, in the case of VPLS, there exists a virtual route for every network connection that is established between each other. As such, it offers much better efficiency than other forms of networking.

In order to understand how this works, you must first understand the characteristics of both the Ethernet standard and the gre protocol. The Ethernet standard on the one hand defines a concept of frame relay, where a router (which can be either private or public) sends and receives data packets. On the other hand, the gre protocol on the other hand defines a form of congestion control wherein routers calculate a minimum guaranteed amount of bandwidth necessary to handle data packets, which are sent and received on their way. This is done by making use of a model called MSS (modulation transfer schedule), which determines how fast data packets are allowed to move between networks. The process is done so that each device that is connected to the network can consume the necessary amount of bandwidth and avoid any loss of information or data.

Just like the standard Ethernet networking, the gre protocol allows for packets to be small in size and has a fixed maximum payload that cannot exceed the maximum value set by the MSS. However, unlike the Ethernet standard, the GRE protocol allows for packets to have a greater maximum payload and smaller size. If the packets in an Ethernet network have a relatively larger size than those in the gre protocol, the latter will take precedence and this is due to the difference in the hop count. For example, if there are ten routers between your application and the application server, the GRE protocol will be used to send ten packets, and the Ethernet network will be affected.

Today, many people use the GRE protocol in conjunction with the Openfaced packet forwarding to create more efficient, reliable, fast and cost-efficient tenant virtual networks. The reason why this works is because the GRE protocol can be configured to work independently of the Openfaced software stack that controls the physical layer of the network. With this feature, GRE tunnels can be created at much faster speeds and can handle large volumes of traffic. This is because the tunnels created within the Openfaced software stack are pre-sized and contain only the necessary portion of the necessary packets to make it through the network.

In addition to being able to establish independent tunnels, the GRE protocol also supports two different layer 3 protocols: Generic Routing Encapsulation (GRC) and Static Routes. GRC is a client-server routing protocol that enables two or more clients to configure the same network in the same manner. It is ideal for short distances or limited sites. On the other hand, Static Routes are used in edge networks where there is no direct path from one end to the other. For example, in a metropolitan area network (MAN), a static route is used for voice traffic and for video network applications. These routes are used for enabling people to connect to the Internet using the same network for both voice and data transmissions.

To understand how the GRE protocol can be useful for VPN users, it is important to know what VPN is and how it works. VPN, or virtual private network, is a type of private network that gives users the ability to surf the Internet as if they are in their own home network. The VPN is usually implemented through the use of a router, referred to as the VPN client, which forwards the traffic between the VPN servers and the public network. This is done through the use of routing protocols, also called protocols or IP-based tools that specify how traffic between networks and servers on the same network should be controlled.

This is how the GRE protocol works. First, the VPN client searches for the nearest GRE gateway that it can find on the Internet. It searches this gateway using the IP address that it has previously set up. When the search is complete, the protocol will then ask for the next number of 16 bits, or zero, to form the address that is to be used in the encryption process.

The next step is for the server, also referred to as the gateway, to encrypt the session. This is done through the negotiation of the destination IP, which is the IP address of the local network that is to be secured. After the connection has been established, the VPN client will be able to establish a secure point-to-Point connection between the local network and the Internet. This point-to-Point connection will be enabled based on the negotiated security parameters. An important thing to note about the GRE protocol is that it is not an efficient means of sending large files through the public network because it requires three bits for each bit of data. The GRE is really just a shortcut for packet switching.