How does GRE | Webwerks

How does GRE


VPN and GRE are tunneling protocols for data transfer through internet. It uses encryption and other methods to enable authorized users to access the network and data. Let's first understand both the protocol of data sharing tunnel. In spite of few similarities, both tunneling methods are significantly different. Below we will see How does GRE and VPN Tunneling work in case of Inter-connected Data Centers. Definition: VPN: VPN is short for Virtual Private Network. It provides a secure encryption to transfer the data among the remote users using internet to connect the company's network. This way it allows only authorized users to access the network maintaining the privacy.

How VPN works ?

Encryption is the key in VPN. Basically it is meant for people who do not have a fixed workstation and have to remotely access business data, emails etc. In such cases, VPN enables secure encrypted data by connecting the authorized users to a private network over the internet, maintaining the privacy as well as secured connection.GRE: GRE is abbreviated for Generic Routing Encapsulation. It is based on virtual tunneling and IP encapsulated protocol, enabling the transfer of packet from one network to the other.

How GRE works?

Here Encapsulation is the key. GRE encapsulates the packets of data in IP tunnels which are routed to an intermediate network from where it is de-encapsulated and redirected to the destination end.

Traffic:VPN uses several IPsec security and encryption mechanisms for sustaining the organizational privacy between the company and its remotely located authorized users. It helps in avoiding any unwanted traffic. GRE enables multi-cast traffic wherein the traffic protocols like ads can be carried forward to other remote sites using GRE tunnel. This feature of multi-cast traffic is not available with VPN.

Agility:GRE is a simple tunneling protocol, utilizing point-to-point switches, hoping in between and redirecting the encapsulated, IP packet. It doesn't require mechanisms and hence it facilitates easy configuration. VPN too is a simple protocol but it requires few installations and software applications. However, both the tunnels have their utilities for connecting remote users.


  • VPN is recommended for users who have to securely access the internally and centrally located data.
  • While GRE is recommended for users who need to forward the traffic over remote sites on an incompatible network.
  • Web Werks offers both GRE and VPN tunneling through its diverse data center locations.
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