3Com SuperStack 4 Configuration Manual page 84

96 C 5: N
HAPTER ETWORK
DHCP Client
Configuration
P O
ROTOCOL PERATION
Figure 23 Typical DHCP Relay Application
DHCP client
Ethernet
DHCP client
DHCP Relay works on the following principle:
When the DHCP client starts and initializes DHCP, it broadcasts the request
■
message to the local network.
If there is a DHCP server on the local network, it can begin DHCP configuration
■
without requiring a DHCP relay function. If not, the local network device
configured for DHCP relay, upon receiving the broadcast message, will forward
the message to the DHCP server on the specified network.
The DHCP server determines a correct configuration based on the information
■
from the client and returns the configuration information back to the client
through DHCP relay.
In fact, several such interactions may be needed to complete a DHCP relay
configuration.
DHCP client configuration is described in the following section.
Configuring a VLAN Interface to Obtain an IP Address Using DHCP
Perform the following configuration in VLAN Interface View.
Table 89 Configuring a VLAN Interface to Obtain an IP Address Using DHCP
Operation
Configure VLAN interface to obtain IP address using
DHCP
Remove the configuration
By default, the VLAN interface does not obtain an IP address using DHCP.
If you are attempting to stop the Switch from transmitting packets, you need to
disable all features which may generate packets. By default these are:
DHCP
■
Resilient ARP
■
Spanning Tree
■
DHCP client
Switch ( DHCP Relay)
DHCP client
Internet
DHCP Server
Command
ip address dhcp-alloc
undo ip address dhcp-alloc