From Wikipedia, the free encyclopedia
Cisco VPN tunneling protocol
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Layer 2 Forwarding Protocol" – news · newspapers · books · scholar · JSTOR (March 2020) (Learn how and when to remove this message) |
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
[edit]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
[edit]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
[edit]References
[edit]External links
[edit]Communication protocols | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Connection applications | |||||||||||
Enterprise software | |||||||||||
Risk vectors | |||||||||||
VPN Services |
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