H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 65)

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NOTE:
•
An interface can be configured to acquire an IP address in multiple ways. The latest configuration
overwrites the previous one.
• Secondary IP addresses cannot be configured on an interface that is enabled with the DHCP client.
• If the IP address that interface A obtains from the DHCP server is on the same network segment as the
IP address of interface B, interface A neither uses the IP address nor requests any IP address from the
DHCP server, unless the IP address of interface B is manually deleted and interface A is brought up
again by first executing the shutdown command and then the undo shutdown command or the DHCP
client is re-enabled on interface A by executing the undo ip address dhcp-alloc command and then the
ip address dhcp-alloc command.
Displaying and maintaining the DHCP client
To do… Use the command… Remarks
Display specified
configuration information
display dhcp client [ verbose ] [ interface
interface-type interface-number ] [ | { begin |
exclude | include } regular-expression ]
Available in any view
DHCP client configuration example
Network requirements
As shown in Figure 23 , on a LAN, Switch B contacts the DHCP server via VLAN-interface 2 to obtain an
IP address, DNS server address, and static route information. The IP address resides on network
10.1.1.0/24. The DNS server address is 20.1.1.1. The next hop of the static route to network 20.1.1.0/24
is 10.1.1.2.
The DHCP server uses Option 121 to assign static route information to DHCP clients. The destination
descriptor field comprises two parts, subnet mask length and destination network address. In this
example, the value of the destination descriptor field takes 18 14 01 01, a hexadecimal number
indicating that the subnet mask length is 24 and destination network address is 20.1.1.0, and the value
of the next hop address field takes 0A 01 01 02, a hexadecimal number indicating that the next hop is
10.1.1.2.
Figure 22 Format of Option 121