Nortel Networks 620 User Manual

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Chapter 6
Advanced Features
E-DOC-CTC-20051017-0169 v0.1
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6.3 Extended Authentication (XAuth)
What is ...
Extended Authentication, commonly referred to as the XAuth protocol, allows for 
performing extra user authentication. A typical practical example is the mixed use 
of IKE tunnel negotiation using preshared key as authentication method and on top 
of that doing Extended Authentication. 
The VPN client functionality built in the SpeedTouch™ supports the (optional) use 
of XAuth. It acts as a XAuth client. In order to use this functionality, it needs to be 
connected to a remote IPSec gateway capable of handling the XAuth protocol. 
The VPN server functionality built in the SpeedTouch™ also supports the use of 
XAuth as an XAuth server. It uses an internal list of authorized users.
How does it work
After the Phase 1 negotiation has been successful (1), the remote IPSec gateway will 
request the XAuth username and password (2). Typically, the remote IPSec device 
will now contact a RADIUS server (3) to check for the credentials. If the XAuth 
authentication is successful, Phase 2 tunnel setup (4) will be initiated.
In the CLI, the XAuth settings are found in the VPNCLIENT and VPNSERVER 
command groups. 
The VPN server in the SpeedTouch™ uses an internal list of authorized 
users. It does not need a RADIUS server to check the credentials.
 
 
   
   
Phase 1
negotiation
XAuth
authentication
Phase 2
negotiation
RADIUS
authentication
RADIUS
server
Remote IPSec
gateway
SpeedTouch
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Black network