Tunneling

Tunneling is the method of transporting network site visitors that makes use of one protocol inside knowledge packets using one other protocol. It permits two gadgets to cover the character of the information throughout the tunnel from different gadgets on the network. Tunneling protocols can encrypt site visitors, present a safe connection for a VPN, or enable packets using an unsupported protocol to journey throughout a network.

All knowledge despatched over a network travels in knowledge packets. Each packet consists of a small header comprising protocol and handle info, adopted by a big knowledge payload containing the transferred knowledge itself. Tunneling takes a complete knowledge packet and turns it into the payload of one other knowledge packet that makes use of a distinct protocol in a course of referred to as “encapsulation.” The different gadgets on the network that carry a packet to its vacation spot can solely see the header of the outer packet and are unaware of the contents of the encapsulated one. Once it reaches its vacation spot, the receiving device decapsulates the packet and accesses its knowledge payload.

The most typical use for tunneling is establishing safe VPN connections over the Internet. A VPN makes use of certainly one of a number of tunneling protocols, like IPsec, L2TP, or PPTP, to encrypt all site visitors between a VPN server and a consumer. However, there are different causes {that a} knowledge switch could require tunneling. In some instances, the network could not help the unique protocol. For instance, if an IPv6 packet must journey over a network that solely helps IPv4, it may be encapsulated inside a suitable IPv4 packet and decapsulated as soon as it reaches the opposite aspect.

Tunneling may also encrypt site visitors using a protocol that doesn’t help encryption by encapsulating it inside a protocol that does. One instance is SFTP, which creates an encrypted SSH tunnel that carries unencrypted FTP site visitors. Finally, tunneling may also help sure kinds of site visitors bypass a network’s firewall by encapsulating restricted site visitors (like P2P file sharing) inside accepted protocols (like HTTP).