Tunneling safely wraps packets inside other packets to protect them on their journey. Tunneling provides the following features:
Masking private addresses ” The IP addresses inside your organization often differ from those on the Internet. Tunneling hides the private IP address during delivery through a public network.
Transporting non-IP payloads ” Tunneling enables you to transport non-IP payloads (such as IPX or AppleTalk packets) through standard OSI stack layers and the Internet by wrapping the payload with an IP and a tunneling protocol header.
Security ” Tunneling can provide added security features such as encryption, authentication, and so on (see the following section "IPsec").
Forwarding ” Tunneling allows data to be relayed to a specific location at the destination, permitting the payload to be processed with more specificity.