Dhcp Relay Agent Configuration Task List - 3Com 4500 PWR 26-Port Configuration Manual

the XID (Transaction ID, a random value selected by
process) in the message, and then forward the message to the DHCP server.
A fter receiving the message, the DHCP server returns a DHCP-ACK message to the client:
If the DHCP-
client without replacing the XID in the message.
If the DHCP-ACK message is broadcast, the DHCP relay agent delivers the message to the CPU
to replace the XID, and then forwards th
A HCP client can only handle a DHCP-ACK message which has the same XID as that in the DHCP D
Info rm message sent by the client. Therefore, to ensure clien
successfully, S4500 series Ethernet switches support the DHCP Inform message handling feature.
W ith this feature enabled, an S4500 series switch that functions as a DHCP relay agent in a fabric can
replace the XID in DHCP Inform messages before forwarding them to the DHCP server. If this feature is
disabled, the switch does not replace the XID.
Con figuring the DHCP Relay Agent
If a switch belongs to an XRN fabric, you need to enable the UDP
configuring it as a DHCP relay agent.
If an S4500 Ethernet switch is configured with DHCP Relay Agent, the
cannot dynamically obtain IP addresses through BOOTP.
DHCP Relay Agent Configuration Task List
Complete the following tasks to configu
Enabling DHCP
Correlating a DHCP Server Group with a Relay Agent Interface
Configuring DHCP Relay Agent S
Configuring the DHCP Relay Agent to Support Option 82
Configuring DHCP Inform Message Handling Feature Used in XRN System
Enabling DHCP
Make sure to enable DHCP before you perform other DHCP relay-related configurations, since other
DHCP-related configurations cannot take effect with DHCP disabled.
ACK message is unicast, the DHCP relay agent directly forwards the message to the
re the DHCP relay agent:
T ask
ecurity Functio
the client to uniquely identify an address allocation
e message to the client.
ts to obtain configuration parameters
ns
40-4
Helper fun ction on it before
clie nts conne cted to it
Rem arks
Required
Required
Optional
Optional
Optional