Changing A Pool's Lease Time - HP ProCurve Secure 7000dl Series Basic Management And Configuration Manual

Dynamic Host Configuration Protocol (DHCP)
Configuring a DHCP Server
13-10

Changing a Pool's Lease Time

Whenever a DHCP server sends a DCHPACK message to a client with its
committed IP address and other network configurations, the server includes
a lease time. This time puts a limit on how long the client can reserve the
address. Temporary leases allow networks to satisfy multiple users with a
limited pool of IP addresses. They also allow users to change addresses
painlessly as the users change location in the network. Typically, active clients
periodically request to keep their addresses before the lease expires so that
data transmission is not interrupted.
The default lease time for DHCP pools on the ProCurve Secure Router is one
day. This setting suits many environments, allowing clients to keep configu-
rations throughout the workday, but also making it easy for a client to receive
a new address when it changes location in the network.
However, subnets for various kinds of users require different lease times. For
example, a subnet that provides public access computers, which are randomly
used by many different people, may need a shorter lease time. Try not to set
the lease shorter than necessary because DHCP exchanges consume band-
width and router processing resources.
You can configure an individual lease time for each DHCP pool established on
the router, according to your organization's policies. For example, you can set
a lease time of 1 hour. From the configuration mode context of the pool, enter:
Syntax: lease <days> <hours> <minutes>
The Secure Router OS always sets the first number entered as the number of
days for the lease, the second as hours, and the third as minutes. You must
enter a zero to indicate that you are skipping a number. For example, to set a
lease time of 15 minutes, enter:
ProCurve(config-dhcp)# lease 0 0 15
You do not have to input zeroes after the last significant number. For example,
a lease time of 30 days is specified as:
ProCurve(config-dhcp)# lease 30
See your ProCurve SROS Command Line Interface Reference Guide for valid
ranges for lease time.