Chapter 9 Forcing Dynamic Reconfiguration Of Clients From A Dhcp Local Server - Juniper EX3400 Features Manual

CHAPTER 9
Forcing Dynamic Reconfiguration of
Clients from a DHCP Local Server
Understanding Dynamic Reconfiguration of Extended DHCP Local Server Clients
Default Client/Server Interaction
Copyright © 2017, Juniper Networks, Inc.
Understanding Dynamic Reconfiguration of Extended DHCP Local Server
Clients on page 111
Configuring Dynamic Client Reconfiguration of Extended Local Server Clients on page 114
Requesting DHCP Local Server to Initiate Reconfiguration of Client Bindings on page 116
Configuring Dynamic Reconfiguration Attempts for DHCP Clients on page 117
Configuring Deletion of the Client When Dynamic Reconfiguration Fails on page 118
Configuring Reconfiguration of the Client on Receipt of RADIUS-Initiated
Disconnect on page 119
Dynamic reconfiguration of clients enables the extended DHCP local server to initiate a
client update without waiting for the client to initiate a request.
Typically the DHCP client initiates all of the basic DHCP client/server interactions. The
DHCP server sends information to a client only in response to a request from that client.
This behavior does not enable a client to be quickly updated with its network address
and configuration in the event of server changes:
NOTE: Technically, the DHCP client/server interactions are the same on
routers and switches. However, the primary usage of this technology on the
routers is for subscriber management. The switches are not used for subscriber
management. Therefore, this topic provides two sample scenarios. The
actions are the same, but the implementation details are different.
On routers—Suppose a service provider restructures its addressing scheme or changes
the server IP addresses that it provided to clients. Without dynamic reconfiguration,
the service provider typically clears the DHCP server binding table, but cannot inform
the DHCP clients that their bindings have been cleared. Consequently, the DHCP client
operates as though its IP address is still valid, but it is now unable to communicate
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