Subscriber Management Procedure; Figure 15: Dhcp External Server - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - BROADBAND ACCESS CONFIGURATION GUIDE 2010-10-12 Configuration Manual

Subscriber Management Procedure

Copyright © 2010, Juniper Networks, Inc.
In the first case, the interface is created when an external DHCP server or the DHCP local
server responds to a subscriber request. In the second case, the subscriber interface is
created when the router receives a packet (the packet detect feature) with a source IP
address that is not in the demultiplexer table. In this second case the primary IP interface
must be in autoconfiguration mode.
Subscriber management uses the following process when validating the IP source address
of the packet:
If the address is not valid, no subscriber interface is created. A discard entry is added
to the demultiplexer table, and an error message is generated.
If the address is valid with respect to the address ranges configured on the primary IP
interface, subscriber management uses packet information to select the appropriate
dynamic subscriber interface profile. The commands corresponding to the profile are
then used to create the subscriber interface.
Figure 15 on page 579 shows a subscriber management environment that includes an
external DHCP server, a RADIUS server, the SRC software, and the DHCP external server
application running on the E Series router.
The E Series router DHCP external server application is used with other JunosE features
to provide subscriber management. Using the router's DHCP external server application
for subscriber management enables you to take advantage of the following features:
Profile assignment—A dynamic subscriber interface profile is associated with a specific
source address by the router's packet detect feature.
Dynamic subscriber interface packet detection and inactivity timer—Subscriber
interfaces are dynamically created based on packet information that is identified by
the packet detection feature. The inactivity timer determines when a dynamic subscriber
interface expires and needs to be deleted.
DHCP external server application—DHCP packets are examined to determine the state
of subscribers.

Figure 15: DHCP External Server

In Figure 15 on page 579, the subscriber requests an address from the DHCP server. The
E Series router DHCP external server application monitors all DHCP communications
Chapter 23: Configuring Subscriber Management
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