D-Link DXS-3600 Series Reference Manual page 350

DXS-3600 Series Layer 3 Managed 10Gigabit Ethernet Switch CLI Reference Guide
Usage Guideline
Use this command in the DHCP Pool Configuration Mode to configure a network for the address pool.
The user cannot configure the manual binding entry in the address pool that was configured with the
network.
When the DHCP server receives a request from a client, the server will select an address pool or subnet
in the address pool based on the following rules for address allocation. When an IP address is allocated
to a host, a binding entry is created.
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If the client is not directly connected to the DHCP server, the discover message is relayed by the
relay agent. The server will select the address pool configured with a subnet that contains the
GIADDR of the packet. If an address pool is selected, the server will try to allocate the address
from the subnet.
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If the client is directly connected to the server, then the server will look for the subnet of the
address pool that contains or match the primary subnet of the received interface. If not found, the
server will look for the subnet of the address pool that contains or match the secondary subnet of
the received interface.
If an address is allocated from a specific subnet, the network mask associated with the subnet will be
replied as the network mask to the user. The network configured for a DHCP address pool can be a
natural network or a sub-network. The configured DHCP address pools are organized as a tree. The root
of the tree is the address pool that contains the natural network. The address pools that contain the sub-
network are branches under the root, and the address pools that contain the manual binding entry is the
leave under the branch or under the root. Based on the tree structure, the child address pool will inherit
the attributes configured for its parent address pool. The only exception to this inheritance is lease
attribute.
Example
This example shows how the subnet 10.1.0.0/16 is configured for the DHCP address pool pool1.
Switch# configure terminal
Switch(config)# ip dhcp pool pool1
Switch(config-dhcp-pool)# network 10.1.0.0/16
Switch(config-dhcp-pool)# default-router 10.1.1.1
Switch(config-dhcp-pool)#
21-24 option
This command is used to configure DHCP server options. Use the no form of this command to remove a
specific option.
option CODE {ascii STRING | hex {HEX-STRING | none} | ip IP-ADDRESS [IP-ADDRESS2...IP-
ADDRESS8]}
no option CODE
Parameters
CODE
ascii STRING
hex {HEX-STRING}
Specifies the DHCP option number in decimals.
Specifies an ASCII string for the DHCP option with a maximum of 255
bytes.
Specifies the hexadecimal format for the DHCP option with a
maximum of 254 characters.
HEX-STRING: Specifies the hexadecimal string for the DHCP option.
none: Specifies the zero-length hexadecimal string.
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