Juniper JUNOSE 11.1.X - BROADBAND ACCESS CONFIGURATION GUIDE 6-4-2010, Configuration Manual

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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.
Subscriber Management Procedure
Figure 15 on page 585 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
Subscriber Management Procedure
■ 585
Chapter 23: Configuring Subscriber Management