Cisco Cisco IOS Software Release 12.2(1)DX
Per VRF AAA
Glossary
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Cisco IOS Release 12.2(1)DX
Glossary
AAA—Authentication, authorization, and accounting. Suite of network security services that provide
the primary framework through which access control can be set up on your Cisco router or access server.
the primary framework through which access control can be set up on your Cisco router or access server.
authentication, authorization, and accounting—See AAA.
L2F—Layer 2 Forwarding. A Layer 2 tunneling protocol that enables an ISP or other access service to
create a virtual tunnel to link customer remote sites or remote users with corporate home networks. In
particular, a network access server (NAS) at the ISP point of presence (POP) exchanges PPP messages
with the remote users and communicates by L2F or L2TP requests and responses with the customer
tunnel server to set up tunnels.
create a virtual tunnel to link customer remote sites or remote users with corporate home networks. In
particular, a network access server (NAS) at the ISP point of presence (POP) exchanges PPP messages
with the remote users and communicates by L2F or L2TP requests and responses with the customer
tunnel server to set up tunnels.
L2TP—Layer 2 Tunnel Protocol. A Layer 2 tunneling protocol that enables an ISP or other access
service to create a virtual tunnel to link customer remote sites or remote users with corporate home
networks. In particular, a network access server (NAS) at the ISP point of presence (POP) exchanges
PPP messages with the remote users and communicates by L2F or L2TP requests and responses with the
customer tunnel server to set up tunnels.
service to create a virtual tunnel to link customer remote sites or remote users with corporate home
networks. In particular, a network access server (NAS) at the ISP point of presence (POP) exchanges
PPP messages with the remote users and communicates by L2F or L2TP requests and responses with the
customer tunnel server to set up tunnels.
L2TP access concentrator—See LAC.
L2TP network server—See LNS.
LAC—L2TP access concentrator. A network access server (NAS) to which the client directly connects
and through which PPP frames are tunneled to the L2TP network server (LNS). The LAC need only
implement the media over which L2TP is to operate to pass traffic to one or more LNSs. The LAC may
tunnel any protocol carried within PPP. The LAC initiates incoming calls and receives outgoing calls. A
LAC is analogous to an L2F network access server.
and through which PPP frames are tunneled to the L2TP network server (LNS). The LAC need only
implement the media over which L2TP is to operate to pass traffic to one or more LNSs. The LAC may
tunnel any protocol carried within PPP. The LAC initiates incoming calls and receives outgoing calls. A
LAC is analogous to an L2F network access server.
LNS—L2TP network server. A termination point for L2TP tunnels, and an access point where PPP
frames are processed and passed to higher-layer protocols. An LNS can operate on any platform that
terminates PPP. The LNS handles the server side of the L2TP protocol. L2TP relies only on the single
medium over which L2TP tunnels arrive. The LNS initiates outgoing calls and receives incoming calls.
An LNS is analogous to a home gateway in L2F technology.
frames are processed and passed to higher-layer protocols. An LNS can operate on any platform that
terminates PPP. The LNS handles the server side of the L2TP protocol. L2TP relies only on the single
medium over which L2TP tunnels arrive. The LNS initiates outgoing calls and receives incoming calls.
An LNS is analogous to a home gateway in L2F technology.
NAS—Network access server. Cisco platform (or collection of platforms such as an AccessPath system)
that interfaces between the packet world (for example, the Internet) and the circuit world (for example,
the Public Switched Telephone Network).
that interfaces between the packet world (for example, the Internet) and the circuit world (for example,
the Public Switched Telephone Network).
network access server—See NAS.
RADIUS—Remote Authentication Dial-In User Service. RADIUS is a distributed client/server system
that secures networks against unauthorized access. In the Cisco implementation, RADIUS clients run on
Cisco routers and send authentication requests to a central RADIUS server that contains all user
authentication and network service access information.
that secures networks against unauthorized access. In the Cisco implementation, RADIUS clients run on
Cisco routers and send authentication requests to a central RADIUS server that contains all user
authentication and network service access information.
Remote Authentication Dial-In User Service—See RADIUS.
virtual private networks—See VPN.
Virtual Routing Forwarding—See VRF.
VPN—A system that permits dial-in networks to exist remotely to home networks, while giving the
appearance of being directly connected. VPNs use L2TP and L2F to terminate the Layer 2 and higher
parts of the network connection at the LNS instead of the LAC.
appearance of being directly connected. VPNs use L2TP and L2F to terminate the Layer 2 and higher
parts of the network connection at the LNS instead of the LAC.
VRF—Virtual Route Forwarding. Initially, a router has only one global default routing/forwarding table.
VRFs can be viewed as multiple disjoined routing/forwarding tables, where the routes of a user have no
correlation with the routes of another user.
VRFs can be viewed as multiple disjoined routing/forwarding tables, where the routes of a user have no
correlation with the routes of another user.