
By default, DHCP external server uses only the MAC address to uniquely identify
DHCP clients. The default setting for DHCP external server is also referred to as
unique MAC mode
.
To enable duplicate MAC mode for the DHCP external server application, you must
issue the
dhcp-external duplicate-mac-address
command from Global Configuration
mode. To restore the default behavior and re-enable unique MAC mode, issue the
no dhcp-external duplicate-mac-address
command.
Configuration Guidelines for Using Duplicate MAC Mode
Observe the following guidelines when you configure the DHCP external server
application to use a combination of the MAC address and giaddr to uniquely identify
DHCP clients, otherwise known as enabling duplicate MAC mode:
■
Unlike other commands for configuring DHCP external server, the
dhcp-external
duplicate-mac-address
command applies globally to all instances of the DHCP
external server application on the router, and is not issued on a per-VR basis.
■
Although the same MAC address can be assigned to more than one DHCP client
in the network, MAC addresses must be unique for each giaddr assigned by a
DHCP relay in the network when duplicate MAC mode is enabled.
■
As is the case with unique MAC mode, client IP addresses managed by the DHCP
external server application must be unique across all VRs configured on the
router.
■
You can configure DHCP external server to support both duplicate MAC mode
(by issuing the
dhcp-external duplicate-mac-address
command) and creation
of subscriber state information based on lease renewals (by issuing the
ip
dhcp-external server-sync
command) simultaneously.
■
DHCP external server supports the following VR topology changes for DHCP
clients regardless of whether duplicate MAC mode is enabled or disabled:
■
A client roams across VRs; this might occur, for example, when a laptop
computer moves to a different building in a campus network.
■
A client is assigned to a different VR; this might occur, for example, when
a quality of service (QoS) policy assigns a client to a different VR during the
DHCP binding process.
■
When DHCP external server is configured to support unique MAC mode, which
is the default, it uses only the MAC address to uniquely identify DHCP clients.
Consequently, when unique MAC mode is enabled, the MAC addresses for all
DHCP clients must be unique across all VRs configured on the router.
Restrictions for Using Duplicate MAC Mode to Manage Clients
The following restrictions apply when you configure the DHCP external server
application to use a combination of the MAC address and giaddr to uniquely identify
DHCP clients, otherwise known as duplicate MAC mode:
■
You can issue the
dhcp-external duplicate-mac-address
command at any time
to enable duplicate MAC mode. However, you
cannot
issue the
no dhcp-external
duplicate-mac-address
command to restore the default setting, unique MAC
DHCP External Server Identification of Clients with Duplicate MAC Addresses Overview
■
521
Chapter 21: Configuring the DHCP External Server Application
Содержание JUNOSE 11.0.X MULTICAST ROUTING
Страница 6: ...vi...
Страница 28: ...xxviii Table of Contents JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 36: ...xxxvi List of Tables JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 42: ...2 Managing Remote Access JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 204: ...164 Managing RADIUS and TACACS JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 274: ...234 CLI Commands Used to Modify RADIUS Attributes JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 292: ...252 Monitoring RADIUS Relay Server JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 336: ...296 RADIUS Client Terminate Reasons JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 368: ...328 Managing L2TP JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 408: ...368 Configuring the Weighted Load Balancing Method JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 444: ...404 PPP Accounting Statistics JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 492: ...452 Monitoring Operational Status within the Current VR Context JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 494: ...454 Managing DHCP JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 510: ...470 DHCP Local Server Configuration Tasks JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 528: ...488 Configuring the Router to Work with the SRC Software JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 556: ...516 Configuring DHCP Relay Proxy JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 616: ...576 Managing the Subscriber Environment JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 632: ...592 Subscriber Management Configuration Examples JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 636: ...596 Monitoring Active IP Subscribers Created by Subscriber Management JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 672: ...632 Monitoring Active IP Subscribers Created by Subscriber Management JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 674: ...634 Managing Subscriber Services JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 767: ...Part 7 Index Index on page 729 Index 727...
Страница 768: ...728 Index JUNOSe 11 0 x Broadband Access Configuration Guide...