3Com 8807 Configuration Manual page 687

Configuring IP Address
Assignment Mode
common to all levels in the address pool structure or some subnets only for the
network segment or for corresponding subnets.
The display dhcp server tree command displays the tree-like structure of address
pool, where address pools on the same level are sorted by the time they are
created.
The dhcp server ip-pool command can be used to create a global DHCP address
pool and enter the corresponding address pool view. If the address pool already
exists, this command brings you to the address pool view directly.
Perform the following configuration in system view.
Table 622 Create a global DHCP address pool
Operation
Create a DHCP address pool and enter the
corresponding DHCP address pool view
Remove a DHCP address pool
By default, no global DHCP address pool is created.
Note that a VLAN interface address pool is created by the system after a legal
unicast IP address is assigned to the VLAN interface and you specify to assign IP
addresses in VLAN interface address pool by using the dhcp select interface
command in VLAN interface view.
IP address can be assigned in two modes: static binding and dynamic assignment.
You can statically bind an IP address in an address pool to the MAC address of a
client or configure a address range to allow the DHCP server dynamic allocate the
addresses in the range to DHCP clients. The two modes cannot coexist in a global
DHCP address pool, but they can coexist in a VLAN interface address pool (but
those that are dynamically assigned have the same network segment as that of
the IP address of the VLAN interface).
For the dynamic assignment mode, you must specify the range of the addresses to
be dynamically assigned. A global DHCP address pool whose IP addresses are
statically bound to DHCP clients is actually a special kind of DHCP address pool.
Configuring static address binding for a global DHCP address pool
fixed IP address to the MAC address of a DHCP client who needs fixed IP address.
After that, when the client requests for an IP address, the DHCP server finds
(according to the MAC address) and assigns the fixed IP address to the client. At
present, only one-to-one MAC-IP binding is supported for global DHCP address
pool.
Perform the following configuration in DHCP address pool view.
Table 623 Configure static address binding for a global DHCP address pool
Operation
Configure an IP address to be statically bound
Configuring DHCP Server
Command
dhcp server ip-pool pool-name
undo dhcp server ip-pool pool-name
Command
static-bind ip-address ip-address [ mask
netmask ]
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