Dhcp Local Server And Address Allocation; Dhcp External Server And Address Allocation; Dhcp Relay Configuration; Supported Configurations - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - BROADBAND ACCESS CONFIGURATION GUIDE 2010-10-12 Configuration Manual

Chapter 25: Configuring Subscriber Interfaces
that has issued a DHCP request. After the DHCP server assigns the IP address and the
router creates the associated dynamic subscriber interface, the subscriber can access
required network services.

DHCP Local Server and Address Allocation

You can configure the DHCP local server to operate in either equal-access mode or
standalone mode.
In standalone mode, the DHCP local server provides a basic DHCP service. The server
receives a client request for an IP address and immediately allocates the subscriber an
IP address from one of the local address pools.
In equal-access mode, the DHCP local server works with Juniper Networks Session and
Resource Control (SRC) software and the authorization, accounting, and address
assignment utility to provide an advanced subscriber configuration and management
service. After the subscriber is authenticated through RADIUS, the DHCP server assigns
the subscriber an IP address with a long lease time. This assignment of an IP address
triggers the creation of dynamic subscriber interfaces.
For more information about the DHCP servers and the SRC software, see the following
chapters:
"DHCP Overview Information" on page 457
SRC-PE Getting Started Guide, Chapter 1, SRC Product Overview

DHCP External Server and Address Allocation

With DHCP external server, all communication between the subscriber and the DHCP
server is monitored by the E Series router. The subscriber requests an address from the
DHCP server through the E Series router. After the subscriber receives an IP address, the
subscriber can access the Internet and use the value-added services provided by the
E Series router and by the SRC software. The edge network must be using a DHCP relay
function.
The services provided by integrating the E Series router's DHCP external server application
with SRC software are similar to those provided when the DHCP local server is integrated
with SRC software. For more information, see SRC-PE Getting Started Guide, Chapter 1,
SRC Product Overview.

DHCP Relay Configuration

When you are configuring dynamic subscriber interface support, and you configure DHCP
relay in the same virtual router as the dynamic subscriber interfaces, you must use the
set dhcp relay inhibit-access-route-creation command to ensure that DHCP replay
does not install access internal routes. Otherwise, DHCP relay will overwrite the access
internal routes that are originally created for the subscriber interface.

Supported Configurations

E Series routers currently support dynamic creation of subscriber interfaces with DHCP
servers in the following configurations:
Copyright © 2010, Juniper Networks, Inc. 603