Troubleshooting Dhcp Server Configuration - HP A5120 EI Series Configuration Manual

The DHCP server assigns PXE server addresses to DHCP clients through Option 43, a self-defined option.
The format of Option 43 and that of the PXE server address sub-option are shown in
19, respectively. The value of Option 43 configured on the DHCP server in this example is 80 0B 00 00
02 01 02 03 04 02 02 02 02. The number 80 is the value of the sub-option type. The number 0B is the
value of the sub-option length. The numbers 00 00 are the value of the PXE server type. The number 02
indicates the number of servers. The numbers 01 02 03 04 02 02 02 02 indicate that the PXE server
addresses are 1.2.3.4 and 2.2.2.2.
Figure 25 Network diagram for self-defined option configuration
Vlan-int2
10.1.1.1/24
Switch A
DHCP server
Configuration procedure
Specify IP addresses for the interfaces (details not shown).
1.
Configure the DHCP server
2.
# Enable DHCP.
<SwitchA> system-view
[SwitchA] dhcp enable
# Enable the DHCP server on VLAN-interface 2.
[SwitchA] interface vlan-interface 2
[SwitchA-Vlan-interface2] dhcp select server global-pool
[SwitchA-Vlan-interface2] quit
# Configure DHCP address pool 0.
[SwitchA] dhcp server ip-pool 0
[SwitchA-dhcp-pool-0] network 10.1.1.0 mask 255.255.255.0
[SwitchA-dhcp-pool-0] option 43 hex 80 0B 00 00 02 01 02 03 04 02 02 02 02
Verification
3.
Switch B can obtain its IP address on 10.1.1.0/24 and PXE server addresses from Switch A. You can use
the display dhcp server ip-in-use command on the DHCP server to view the IP addresses assigned to the
clients.

Troubleshooting DHCP server configuration

Symptom
A client's IP address obtained from the DHCP server conflicts with another IP address.
Analysis
A host on the subnet may have the same IP address.
Solution
Disable the client's network adapter or disconnect the client's network cable. Ping the client's IP
1.
address from another host to check whether there is a host using the same IP address.
Vlan-int2
Switch B
DHCP client
48
Figure 17 and Figure