Configuring A Dhcp/Bootp Client; Dhcp Client Configuration Example - 3Com 4500 Configuration Manual

Configuring a DHCP/BOOTP Client

Follow these steps to configure a DHCP/BOOTP client:
To do...
Enter system view
Enter VLAN interface view
Configure the VLAN interface
to obtain IP address through
DHCP or BOOTP
Currently, an S4500 Ethernet switch functioning as the DHCP client can use an IP address for 24
days at most. That is, the DHCP client can obtain an address lease for no more than 24 days even
though the DHCP server offers a longer lease period.
If a switch belongs to an XRN fabric, you need to enable the UDP Helper function on the switch
before configuring its VLAN interfaces to obtain IP addresses through DHCP.
To improve security and avoid malicious attack to the unused SOCKETs, S4500 Ethernet switches
provide the following functions:
UDP 67 and UDP 68 ports used by DHCP are enabled only when DHCP is enabled.
UDP 67 and UDP 68 ports are disabled when DHCP is disabled.
The specific implementation is:
Using the ip address dhcp-alloc command enables the DHCP client, and UDP port 68.
Using the undo ip address dhcp-alloc command disables the DHCP client, and UDP port 68.

DHCP Client Configuration Example

Network requirements
Using DHCP, VLAN-interface 1 of Switch B is connected to the LAN to obtain an IP address from the
DHCP server.
Use the command...
system-view
interface vlan-interface
vlan-id
ip address { bootp-alloc |
dhcp-alloc }
4-2
Remarks
—
—
Required
By default, no IP address is
configured for the VLAN
interface.