Chapter 21 Dhcp Relay; Overview; Dhcp Relay Configuration - ZyXEL Communications Dimension GS-3012F User Manual

This chapter describes the DHCP relay and shows you how to configure the DHCP Relay screen.

21.1 Overview

DHCP (Dynamic Host Configuration Protocol, RFC 2131 and RFC 2132) allows individual clients to obtain
TCP/IP configuration at start-up from a DHCP server. You can configure the switch to relay client TCP/IP
configuration requests to a DHCP server and the server's responses back to the clients.
21.1.1 DHCP "Relay Agent Information Option"
The switch can add information to client TCP/IP configuration requests that it relays to a DHCP server. This helps
provide authentication about the source of the requests. You can also specify additional information for the switch
to add to the client TCP/IP configuration requests that it relays to the DHCP server. Please refer to RFC 3046 for
more details.
21.1.2 DHCP Relay Agent Circuit ID Sub-option Format
The DHCP relay agent information feature adds an Agent Information field to the option 82 field of the DHCP
headers of client TCP/IP configuration request frames that the switch relays to a DHCP server. The Agent
Information field that the switch adds contains an "Agent Circuit-ID sub-option" that includes the port number,
VLAN ID and optional information about the port where the TCP/IP configuration request was received.

21.2 DHCP Relay Configuration

To configure DHCP relay information and specify the DHCP server(s), click Advanced Application and DHCP
Relay to display the screen as shown next.
DHCP Relay
GS-3012F User's Guide
Chapter 21
DHCP Relay
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