TunnelingIntroduction

• Definition

 http://en.wikipedia.org/wiki/Tunneling_protocol

 "A tunneling protocol is a network protocol which encapsulates one protocol or session inside another. Protocol A is encapsulated 
within protocol B, such that A treats B as though it were a data link layer. Tunneling may be used to transport a network protocol 
through a network which would not otherwise support it. Tunnelling may also be used to provide various types of VPN functionality 
such as private addressing."

e.g. : a transit network unsupporting a specific protocol (DECnet), the need to provide confidentiality and integrity for a specific network stream…

• Type of Tunneling
  • Stream oriented (e.g. SSL/TLS)
  • Datagram "packet" oriented (e.g. IPsec, PPP)
• Security of Tunneling (scope and users)
  • Tunneling can be used by attackers but also used for legitimate communication (always keep in mind the duality of tunneling usage)
• GRE
• PPP
• PPTP
• IPsec

 ** OK

• OpenVPN?

• SSH (SECSH)

 ** OK