4000 Router Series Layer 2 - WAN Configuration Guide

Table 1 Tunnel attributes that can be issued by the RADIUS server

Attribute number Attribute name Description

64 Tunnel-Type Tunnel type, which can only be L2TP.

65 Tunnel-Medium-Type

Transmission medium type for the tunnel, which can

only be IPv4.

67 Tunnel-Server-Endpoint IP address of the LNS.

69 Tunnel-Password Key used to authenticate a peer of the tunnel.

81 Tunnel-Private-Group-ID

Group ID for the tunnel.

The LAC sends this value to the LNS for the LNS to

perform an operation accordingly.

82 Tunnel-Assignment-ID

Assignment ID for the tunnel.

It is used to indicate the tunnel to which a session is

assigned. L2TP users with same Tunnel-Assignment-ID,

Tunnel-Server-Endpoint, and Tunnel-Password attributes

share an L2TP tunnel.

The RADIUS server can issue only one set of the L2TP tunnel attributes in a RADIUS packet.

The RADIUS-issued tunnel attributes will override the tunnel attributes you have manually

configured on the LAC, but not vice versa.

Protocols and standards

• RFC 1661, The Point-to-Point Protocol (PPP)

• RFC 1918, Address Allocation for Private Internets

• RFC 2661, Layer Two Tunneling Protocol "L2TP"

• RFC 2868, RADIUS Attributes for Tunnel Protocol Support

L2TP configuration task list

When you configure L2TP, perform the following operations:

1. Determine the network devices needed according to the networking environment. For

NAS-initiated mode and LAC-auto-initiated mode, configure both the LAC and the LNS. For

client-initiated mode, you only need to configure the LNS.

2. Configure the devices accordingly, based on the intended role (LAC or LNS) on the network.

To configure a device as an LAC in NAS-initiated or LAC-auto-initiated mode, complete the following

tasks:

Tasks at a

lance

Remarks

(Required.) Configuring basic L2TP capabilities N/A