C613-16070-00 REV B
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Introduction
This document covers a range of examples on how to configure Allied Telesis and Cisco routers
to interoperate over Layer 2 Tunnelling Protocol (L2TP). The two main components that make
up L2TP are the L2TP Access Concentrator (LAC), which is the device that physically terminates
a call and the L2TP Network Server (LNS), which is the device that terminates and potentially
authenticates the PPP stream.
What information will you find in this document?
This document contains the following sections:
• Example 1 - Cisco as LAC, Allied Telesis router as LNS, no RADIUS, on page 2
• Example 2 - Cisco as LAC, Allied Telesis router as LNS, using RADIUS to pass L2TP
parameters to the LAC, on page 4
• Example 3 - Cisco as LNS, Allied Telesis router as LAC, on page 7
• Example 4 - Cisco and Allied Telesis router as peers over a Virtual tunnel, on page 9
Which products and software versions does this information apply to?
•
Products:
Rapier, AT-8800, AT-8900, AT-9900, AT-9800 and SwitchBlade series switches
AR400 and AR700 series routers
• Software versions: 2.7.1 and later
Configure Allied Telesis and Cisco routers to
interoperate over L2TP
How To |
Configure Allied Telesis and Cisco routers to interoperate over L2TP 2
Example 1 - Cisco as LAC, Allied Telesis router as LNS, no
RADIUS
In this example the LAC is configured with a Virtual Private Dial-up Network (VPDN) group, which
specifies the IP address of the LNS and the L2TP username, and is associated with a matching entry
in the user database containing the password to send to the LNS for L2TP authentication.
Some points to note:
a On the Client router:
In this particular setup it is not really necessary to configure a username with a domain suffix as
it is being authenticated locally by the LNS rather than by RADIUS.
b On the LAC:
Under "vpdn-group 1" the local name "lac" is what the router will send to the LNS as its L2TP
username. If no local name is configured the router’s hostname will be used instead.
c On the LNS:
Allied Telesis routers do not have an equivalent to Cisco’s "local name" command. The system
name of the Allied Telesis router is always used as the L2TP username
Client Router Configuration
set system name="user"
add isdn call=l2tp number=12345 precedence=out
create ppp=0 idle=60 over=isdn-l2tp
set ppp=0 iprequest=on username="username@domain.com" password="password"
enable ip
enable ip remote
add ip int=ppp0 ip=0.0.0.0
add ip int=eth0 ip=192.168.1.1
Host
Client Router
Cisco LAC
AR Router LNS
ISDN
eth0
eth0
eth0
BRI0
BRI0