H3C Technologies H3C S3600 Series Switches - Manual (Page 703)

6-2
Configuring a DHCP/BOOTP Client
Follow these steps to configure a DHCP/BOOTP client:
To do… Use the command… Remarks
Enter system view system-view —
Enter VLAN interface view
interface vlan-interface
vlan-id
—
Configure the VLAN interface
to obtain IP address through
DHCP or BOOTP
ip address { bootp-alloc |
dhcp-alloc }
Required
By default, no IP address is
configured for the VLAN
interface.
z Currently, an S3600 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.
z If a switch belongs to an IRF 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, S3600 Ethernet switches
provide the following functions:
z UDP 67 and UDP 68 ports used by DHCP are enabled only when DHCP is enabled.
z UDP 67 and UDP 68 ports are disabled when DHCP is disabled.
The specific implementation is:
z Using the ip address dhcp-alloc command enables the DHCP client, and UDP port 68.
z 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.
Network diagram
See Figure 2-1 .
Configuration procedure
The following describes only the configuration on Switch B serving as a DHCP client.
# Configure VLAN-interface 1 to dynamically obtain an IP address by using DHCP.