3Com 5500-SI Switch User Manual


 
134 CHAPTER 10: DHCP SERVER CONFIGURATION
bound to a DHCP client to come from a special DHCP address pool that contains only
the IP address.
Configuring to assign IP addresses by static binding
Some DHCP clients, such as WWW servers, need to be assigned fixed IP addresses.
This is achieved by binding IP addresses to the MAC addresses of these DHCP clients.
When a DHCP client that is of this kind applies for an IP address, the DHCP server
searches for the IP address corresponding to the MAC address of the DHCP client and
then assign the IP address to the DHCP client.
Configuring to assign IP addresses dynamically
As an interface-based address pool is created after the interface is assigned a valid
unicast IP address, the IP addresses contained in the address pool belong to the
network segment where the interface resides in and are available to the interface
only. So specifying the range of the IP addresses to be dynamically assigned is
unnecessary.
To avoid IP address conflicts, the IP addresses to be dynamically assigned to DHCP
clients are those that are not occupied by specific network devices (such as gateways
and FTP servers).
The lease time can differ with address pools. But that of the IP addresses of the same
address pool are the same. Lease time is not inherited.
Table 122 Configure to assign IP addresses by static binding
Operation Command Description
Enter system view system-view -
Enter interface view interface interface-type
interface-number
-
Bind an IP address to
the MAC address of a
DHCP client statically
dhcp server static-bind
ip-address ip-address
mac-address mac-address
Required
By default, no IP address is statically
bound to a MAC address.
Table 123 Configure to assign IP addresses dynamically
Operation Command Description
Enter system view system-view -
Configure the lease
time
Configure for the
current interface
interface
interface-type
interface-number
Optional
The default lease time is one
day.
dhcp server expired {
day day [ hour hour [
minute minute ] ] |
unlimited }
quit
Configure multiple
interfaces
dhcp server expired {
day day [ hour hour [
minute minute ] ] |
unlimited } { interface
interface-type
interface-number [
to interface-type
interface-number ] |
all }