Cisco 10000 - Manual (Page 187)

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Cisco 10000 Series Router Software Configuration Guide
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Chapter 5 Configuring the Layer 2 Tunnel Protocol Access Concentrator and Network Server
L2TP Network Server
• Tunnel Accounting, page 5-25
• Tunnel Authentication, page 5-25
• Named Method Lists, page 5-27
• Framed-Route VRF Aware, page 5-27
• Feature History for LNS, page 5-28
• Restrictions for the LNS, page 5-28
• Prerequisites for LNS, page 5-28
• Required Configuration Tasks for LNS, page 5-29
• Optional Configuration Tasks for LNS, page 5-30
• Configuration Examples for LNS, page 5-45
• Monitoring and Maintaining LNS, page 5-51
Virtual Template Interface
The virtual template interface is a logical entity that the Cisco 10000 series router applies dynamically
as needed to a connection. It is a configuration for an interface, but it is not tied to the physical interface.
It is used to create and configure a virtual interface known as a virtual access interface (VAI). The VAI
is cloned from the virtual template interface, used on demand, and then freed when no longer needed.
For example, when a remote user initiates a PPP session to the Cisco 10000 series router, the predefined
configuration template is used to configure a VAI. The VAI is created and configured dynamically using
the virtual template interface. Using AAA, RADIUS attributes can further define the VAI configuration.
The VAI uses the attributes of the virtual template to create the session, which results in a VAI that is
uniquely configured for a specific user. When the user is done, the VAI goes down and the resources are
freed for other client uses.
Virtual Routing and Forwarding Instance
A virtual routing and forwarding (VRF) instance includes the routing information that defines a
customer VPN site that is attached to a provider edge (PE) router, such as the Cisco 10000 series router.
A VRF consists of an IP routing table, a derived forwarding table, a set of interfaces that use the
forwarding table, and a set of rules and routing protocols that determine what goes into the forwarding
table.
To configure a VRF instance, enter the rd command in VRF configuration submode to specify the
correct route distinguisher (RD) used for the VPN. The RD extends the IP address so that you can
identify the VPN to which it belongs.
Per VRF AAA
The per VRF AAA feature enables you to partition authentication, authorization, and accounting (AAA)
services based on a VRF instance. To support the per VRF AAA feature, the RADIUS server must be
VRF aware.