L2F, or Layer 2 Forwarding, is a
tunneling protocol
In computer networks, a tunneling protocol is a communication protocol which allows for the movement of data from one network to another. They can, for example, allow private network communications to be sent across a public network (such as the ...
developed by
Cisco Systems, Inc. to establish
virtual private network
Virtual private network (VPN) is a network architecture for virtually extending a private network (i.e. any computer network which is not the public Internet) across one or multiple other networks which are either untrusted (as they are not con ...
connections over the Internet. L2F does not provide
encryption
In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the inf ...
or
confidentiality
Confidentiality involves a set of rules or a promise sometimes executed through confidentiality agreements that limits the access to or places restrictions on the distribution of certain types of information.
Legal confidentiality
By law, la ...
by itself; It relies on the protocol being tunneled to provide
privacy
Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively.
The domain of privacy partially overlaps with security, which can include the concepts of a ...
. L2F was specifically designed to tunnel
Point-to-Point Protocol
In computer networking, Point-to-Point Protocol (PPP) is a data link layer (layer 2) communication protocol between two routers directly without any host or any other networking in between. It can provide loop detection, authentication, transmissio ...
(PPP) traffic.
RFC2341 on IETF.org
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Use
Virtual dial-up allows many separate and autonomous protocol domains to share common access infrastructure including modems, Access Servers, and ISDN routers. RFCs prior to 2341 have specified protocols for supporting IP dial-up via SLIP
Slip or The Slip may refer to:
* Slip (clothing), an underdress or underskirt
Music
* The Slip (band), a rock band
* ''Slip'' (album), a 1993 album by the band Quicksand
* ''The Slip'' (album) (2008), a.k.a. Halo 27, the seventh studio al ...
and multiprotocol dial-up via PPP.
L2F packet structure
Other VPN protocols
* IPsec
*L2TP Layer 2 Tunneling Protocol
In computer networking, Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs) or as part of the delivery of services by ISPs. It uses encryption ('hiding') only for its own control messages (usi ...
*PPTP Point-to-Point Tunneling Protocol
The Point-to-Point Tunneling Protocol (PPTP) is an obsolete method for implementing virtual private networks. PPTP has many well known security issues.
PPTP uses a TCP control channel and a Generic Routing Encapsulation tunnel to encapsulate ...
References
External links
L2F on Cisco.com
RFC2341 on IETF.org
RFC2341 on RFC Archive
{{VPN
Cisco protocols