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Cisco Router and Security Device Manager Version 2.2 User’s Guide
OL-4015-08
Glossary
key pair See public key encryption.
key recovery A trusted method by which encrypted information can be decrypted if the
decryption key is lost or destroyed.
L
L2F Protocol Layer 2 Forwarding Protocol. Protocol that supports the creation of secure
virtual private dial-up networks over the Internet.
L2TP Layer 2 Tunneling Protocol. An Internet Engineering Task Force (IETF)
standards track protocol defined in RFC 2661 that provides tunneling of PPP.
Based upon the best features of L2F and PPTP, L2TP provides an industry-wide
interoperable method of implementing VPDN. L2TP is proposed as an IPSec
alternative, but is used sometimes alongside IPSec to provide authentication
services.
LAC L2TP access concentrator. Device terminating calls to remote systems and
tunneling PPP sessions between remote systems and the LNS.
LAN Local Area Network. A network residing in one location or belonging to one
organization, typically, but not necessarily using IP and other Internet protocols.
Not the global Internet. See also intranet, network, Internet.
LAPB Link Access Procedure, Balanced.
LBO Line Build Out.
life cycle See expiration date.
LNS L2TP network server. Device able to terminate L2TP tunnels from a LAC and
able to terminate PPP sessions to remote systems through L2TP data sessions.
local subnet Subnetworks are IP networks ar bitrarily segmented by a network administrator
(by means of a subnet mask) in order to provide a multilevel, hierarchical routing
structure while shielding the subnetwork from the addressing complexity of
attached networks. The local subnet is the subnet ass ociated with your end of a
transmission.