3Com Switch 7754, Configuration Manual

Page: 596 / 940

596 C
HAPTER
57: DHCP S
ERVER
C
ONFIGURATION
Configuring How to
Assign IP Addresses in a
Global Address Pool
You can specify to bind an IP address in a global address pool statically to a DHCP
client or assign IP addresses in the pool dynamically to DHCP clients as needed. In
the global address pool, you can bind an IP address statically to a DHCP client and
assign other IP addresses in the pool dynamically to DHCP clients.
For dynamic IP address assigning, you need to specify the range of the IP addresses
to be dynamically assigned. But for static IP address binding, you can consider an
IP address statically bound to a DHCP client coming from a special DHCP address
pool that contains only one IP address.
Configuring to assign IP addresses by static binding
Some DHCP clients, such as WWW servers, need fixed IP addresses. This can be
achieved by binding IP addresses to the MAC addresses of these DHCP clients.
When such a DHCP client applies for an IP address, the DHCP server searches for
the IP address corresponding to the MAC address of the DHCP client and assigns
the IP address to the DHCP client.
Currently, only one IP address in a global DHCP address pool can be statically
bound to a MAC address.
n
■
The static-bind ip-address command and the static-bind mac-address
command must be coupled.
■
In the same global DHCP address pool, if the static-bind ip-address
command or the static-bind mac-address command is executed repeatedly,
the new configuration overwrites the previous one.
■
The IP address to be statically bound cannot be an interface IP address of the
DHCP server; otherwise static binding does not take effect.
■
A client can permanently use the statically-bound IP address that it has
obtained. The IP address is not limited by the lease time of the IP addresses in
the address pool.
Configuring to assign IP addresses dynamically
IP addresses dynamically assigned to DHCP clients (including those that are
permanently leased and those that are temporarily leased) belong to addresses
segments that are previously specified. Currently, an address pool can contain only
one address segment, whose ranges are determined by the subnet mask.
Table 464 Configure to assign IP addresses by static binding
Operation Command Description
Enter system view system-view -
Create a DHCP address pool
and enter DHCP address pool
view dhcp server ip-pool
pool-name
Required
By default, no global DHCP
address pool is created
Configure an IP address to be
statically bound static-bind ip-address
ip-address [ mask mask ]
Required
By default, no IP address is
statically bound
Configure a client MAC
address to which an IP
address is to be statically
bound static-bind mac-address
mac-address
Required
By default, no MAC address
to which an IP address is to be
statically bound is configured