Enlace
virtual entre dos dispositivos utilizando una infraestructura previa. Hay
diferentes técnicas para crear un túnel: encapsular el protocolo, conmutar por
etiquetas, o crear circuitos virtuales. El túnel permite que las entidades
conectadas utilicen protocolos que soporta la red subyacente.
Technology enabling one
network to send its data via another network’s connections. Tunneling works by
encapsulating a network protocol within packets carried by the second network.
[CNSSI_4009:2010]
1. (I) A communication
channel created in a computer network by encapsulating (i.e., layering) a
communication protocol's data packets in (i.e., above) a second protocol that
normally would be carried above, or at the same layer as, the first one. (See:
L2TP, tunnel mode, VPN. Compare: covert channel.) [RFC4949:2007]
Data path between networked
devices which is established across an existing network infrastructure by
using techniques such as protocol
encapsulation, label switching, or virtual circuits. [ISO-18028-1:2006]
A communication channel
created in a computer network by encapsulating a communication protocol's data
packets in (on top of) a second protocol that normally would be carried above,
or at the same layer as, the first one. Most often, a tunnel is a logical point-to-point
link - i.e., an OSI layer 2 connection - created by encapsulating the layer 2
protocol in a transport protocol (such as TCP), in a network or Internetwork
layer protocol (such as IP), or in another link layer protocol. Tunneling can
move data between computers that use a protocol not supported by the network
connecting them.
http://www.sans.org/security-resources/glossary-of-terms/
Le principe de
tunneling consiste à utiliser un réseau public non sécurisé (ex.: Internet)
comme élément/extension d'un réseau privé sécurisé. On utilise ainsi les
capacités de télécommunication de l'Internet en ajoutant une couche de sécurité
afin d'établir un VPN. Sont souvent utilisés les protocoles PPTP, L2TP ou IPSEC
pour établir cette couche supplémentaire de sécurité.
http://securit.free.fr/glossaire.htm