Sequence Of Events On The Lns - Juniper JUNOSE SOFTWARE 11.2.X - BROADBAND ACCESS CONFIGURATION GUIDE 7-20-2010 Configuration Manual

JunosE 11.2.x Broadband Access Configuration Guide

Sequence of Events on the LNS

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By using either a local database related to the domain name or RADIUS
3.
authentication, the router determines either to terminate or to tunnel the PPP
connection.
If the router discovers that it should tunnel the session, it does the following:
4.
a. Sets up a new destination or selects an existing destination.
b. Sets up a new tunnel or selects an existing tunnel.
c. Opens a new session.
The router forwards the results of the LCP negotiations and authentication to the
5.
LNS.
A PPP connection now exists between the client and the LNS.
NOTE: The router discards received packets if the size of the variable-length, optional
offset pad field in the L2TP header is too large. The router always supports packets
that have an offset pad field of up to 16 bytes, and may support larger offset pad fields,
depending on other information in the header. This restriction is a possible, although
unlikely, cause of excessive discarding of L2TP packets.
The E Series router sets up an LNS as follows:
An LAC initiates a tunnel with the router.
1.
The router verifies that a tunnel with this LAC is valid—destination configured,
2.
hostname and tunnel password correct.
The router completes the tunnel setup with the LAC.
3.
The LAC sets up a session with the router.
4.
The router creates a dynamic PPP interface on top of the session.
5.
If they are enabled and present, the router takes the proxy LCP and the proxy
6.
authentication data and passes them to PPP.
The E Series PPP processes the proxy LCP, if it is present, and, if acceptable, places
7.
LCP on the router in opened state without renegotiation of LCP.
NOTE: If proxy LCP is not present or not acceptable, the router negotiates LCP with the
remote system.
The E Series PPP processes the proxy authentication data, if it is present, and passes
8.
the data to AAA for verification. (If the data is not present, E Series PPP requests the
data from the remote system.)
The router passes the authentication results to the remote system.
9.
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