H3C Technologies H3C S5560 Series Switches - Manual (Page 67)

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[SwitchA-dhcp-pool-aa]
Verifying the configuration
# Verify that the DHCP server assigns clients IP addresses and gateway address from the secondary
subnet when no address is available from the primary subnet. (Details not shown.)
# Display the primary and secondary subnet IP addresses the DHCP server has assigned.
[SwitchA] display dhcp server ip-in-use
DHCP option customization configuration example
Network requirements
As shown in Figure 20 , the DHCP client (Switch B) obtains an IP address and PXE server addresses from
the DHCP server (Switch A). The IP address belongs to subnet 10.1.1.0/24. The PXE server addresses are
1.2.3.4 and 2.2.2.2.
The DHCP server assigns PXE server addresses to DHCP clients through Option 43, a customized option.
The format of Option 43 and that of the PXE server address sub-option are shown in Figure 13 and Figure
15 . 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 20 Network diagram
Configuration procedure
1. Specify IP addresses for the interfaces. (Details not shown.)
2. Configure the DHCP server:
# Enable DHCP.
system-view
[SwitchA] dhcp enable
# Enable the DHCP server on VLAN-interface 2.
[SwitchA] interface vlan-interface 2
[SwitchA-Vlan-interface2] dhcp select server
[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 800B0000020102030402020202