User Guide

Chapter 4. Configuring Special Features 75
3. If the client
and
subnetwork lease options are both “default”, then the server goes up one level
(global) and uses the lease time defined at the global level (server).
4. Lease time:
The minimum lease time is 1 hour.
The global default is 168 hours.
!
!!
!
Commands
The following commands are used by network administrators to control lease time.
To set the lease time explicitly for the client lease, use:
dhcp set lease <
ipaddr
> <
hours
>
To set the lease time explicitly for the subnetwork lease, use:
dhcp set lease <
net
> <
hours
>
To set the lease time explicitly for the global lease, use:
dhcp set lease <
hours
>
Example 1:
To set the lease time to “default” for the client 192.168.254.17, type:
dhcp set lease 192.168.254.17 default
Example 2:
To set the subnetwork lease time to infinite for the subnet 192.168.254.0, type:
dhcp set lease 192.168.254.0 infinite
Example 3:
To set the global lease time to 2 hours, type:
dhcp set lease 2
Manually Changing Client Leases
Administrators will generally not need to change client leases manually. However, if the need arises to do so,
use the following two commands.
Warning
: The client will not be aware that the administrator has changed or released a client lease!
To change the client lease expiration time to a given value:
dhcp set expire <
ipaddr
> <
hours
>
Setting the expiration time to “default” will cause the server to compute the lease time using the algorithm as
described in Section C
, Setting the lease time
.
To release the client lease so it becomes available for other assignments:
dhcp clear expire <
ipaddr
>
Setting Option Values
Administrators will want to set the values for global options, for options specific to a subnetwork, or for options
specific to a client lease.
Note:
See RFC 2131/2132 for the description of various options.