ZyXEL Communications GS2200 Series, User Manual

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GS2200 Series User’s Guide
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H A P T E R
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DHCP
32.1 DHCP Overview
This chapter shows you how to configure the DHCP feature.
DHCP (Dynamic Host Configuration Protocol RFC 2131 and RFC 2132) allows individual computers
to obtain TCP/IP configuration at start-up from a server. If you configure the Switch as a DHCP relay
agent, then the Switch forwards DHCP requests to DHCP server on your network. If you don’t
configure the Switch as a DHCP relay agent then you must have a DHCP server in the broadcast
domain of the client computers or else the client computers must be configured manually.
32.1.1 What You Can Do
• Use the DHCP Status screen ( Section 32.2 on page 239 ) to display the relay mode.
• Use the DHCP Relay screen ( Section 32.3 on page 240 ) to enable and configure global DHCP
relay.
• Use the VLAN Setting screen ( Section 32.4 on page 241 ) to configure your DHCP settings based
on the VLAN domain of the DHCP clients.
32.1.2 What You Need to Know
Read on for concepts on DHCP that can help you configure the screens in this chapter.
DHCP Modes
If there is already a DHCP server on your network, then you can configure the Switch as a DHCP
relay agent. When the Switch receives a request from a computer on your network, it contacts the
DHCP server for the necessary IP information, and then relays the assigned information back to the
computer.
DHCP Configuration Options
The DHCP configuration on the Switch is divided into Global and VLAN screens. The screen you
should use for configuration depends on the DHCP services you want to offer the DHCP clients on
your network. Choose the configuration screen based on the following criteria:
• Global: The Switch forwards all DHCP requests to the same DHCP server.
• VLAN: The Switch is configured on a VLAN by VLAN basis. The Switch can be configured to relay
DHCP requests to different DHCP servers for clients in different VLAN.