D-Link DWS-4026 Product Manual - Page 290

Managing the BOOTP/DHCP Relay Agent

Page 290 highlights

D-Link Unified Access System Software User Manual 12/10/09 MANAGING THE BOOTP/DHCP RELAY AGENT BootP/DHCP Relay Agent enables BootP/DHCP clients and servers to exchange BootP/DHCP messages across different subnets. The relay agent receives the requests from the clients, and checks the valid hops and giaddr fields. If the number of hops is greater than the configured, the agent assumes the packet has looped through the agents and discards the packet. If giaddr field is zero the agent must fill in this field with the IP address of the interface on which the request was received. The agent unicasts the valid packets to the next configured destination. The server responds with a unicast BOOTREPLY addressed to the relay agent closest to the client as indicated by giaddr field. Upon reception of the BOOTREPLY from the server, the agent forwards this reply as broadcast or unicast on the interface that had received the BOOTREQUEST. This interface can be identified by giaddr field. The Unified Switch also supports DHCP relay agent options to identify the source circuit when customers are connected to the Internet with high-speed modem. The relay agent inserts these options when forwarding the request to the server and removes them when sending the reply to the clients. If an interface has more than one IP address, the relay agent should use the primary IP address configured as its relay agent IP address. The following pages configure and display BOOTP/DHCP relay agent: • "BOOTP/DHCP Relay Agent Configuration" • "BOOTP/DHCP Relay Agent Status" Page 290 Managing the BOOTP/DHCP Relay Agent Document 34CSFP6XXUWS-SWUM100-D7

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D-Link Unified Access System
Software User Manual
12/10/09
Page
290
Managing the BOOTP/DHCP Relay Agent
Document
34CSFP6XXUWS-SWUM100-D7
M
ANAGING
THE
BOOTP/DHCP R
ELAY
A
GENT
BootP/DHCP Relay Agent enables BootP/DHCP clients and servers to exchange BootP/DHCP messages across different
subnets. The relay agent receives the requests from the clients, and checks the valid hops and giaddr fields. If the number
of hops is greater than the configured, the agent assumes the packet has looped through the agents and discards the packet.
If giaddr field is zero the agent must fill in this field with the IP address of the interface on which the request was received.
The agent unicasts the valid packets to the next configured destination. The server responds with a unicast BOOTREPLY
addressed to the relay agent closest to the client as indicated by giaddr field. Upon reception of the BOOTREPLY from the
server, the agent forwards this reply as broadcast or unicast on the interface that had received the BOOTREQUEST. This
interface can be identified by giaddr field.
The Unified Switch also supports DHCP relay agent options to identify the source circuit when customers are connected to
the Internet with high-speed modem. The relay agent inserts these options when forwarding the request to the server and
removes them when sending the reply to the clients.
If an interface has more than one IP address, the relay agent should use the primary IP address configured as its relay agent
IP address.
The following pages configure and display BOOTP/DHCP relay agent:
“BOOTP/DHCP Relay Agent Configuration”
“BOOTP/DHCP Relay Agent Status”