Layer 2 Forwarding Protocol
L2F, or Layer 2 Forwarding, is a tunneling protocol developed by Cisco Systems, Inc. to establish virtual private network connections over the Internet. L2F does not provide encryption or confidentiality by itself; It relies on the protocol being tunneled to provide privacy. L2F was specifically designed to tunnel Point-to-Point Protocol (PPP) traffic.[1]
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 and multiprotocol dial-up via PPP.
L2F packet structure
Bits 0-12 | 13-15 | 16-23 | 24-31 | ||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
F | K | P | S | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | C | Ver | Protocol | Sequence (opt) | ||||||||||||||||
Multiplex ID | Client ID | ||||||||||||||||||||||||||||||
Length | Payload offset (opt) | ||||||||||||||||||||||||||||||
Packet key (optional) | |||||||||||||||||||||||||||||||
Payload | |||||||||||||||||||||||||||||||
L2F Checksum (opt) |
Other VPN protocols
References
External links
This article is issued from Wikipedia - version of the 3/26/2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.