GRE Tunnel
What is a GRE Tunnel? A GRE (Generic Routing Encapsulation) tunnel is a protocol developed by Cisco that encapsulates a wide variety of network layer protocols inside virtual point-to-point links over an IP network . Essentially, it allows for the creation of a private, secure, and isolated path between two endpoints over a public or untrusted network, like the Internet . Why is it Used? GRE tunnels are used for several reasons: Protocol Encapsulation : GRE can encapsulate a variety of network layer protocols, enabling the transport of protocols that might not be natively supported by the underlying network . Multicast Traffic : Unlike some other tunneling protocols, GRE supports multicast traffic, making it suitable for dynamic routing protocols . Simplified Connectivity : It simplifies the setup of VPNs and other network connections by creating a virtual point-to-point link . Interoperability : GRE is defined in RFC 2784, making it widely supported across different vendors . Pros an...