User manual

Chapter 4 - Layer 3 Command Set - IP Networking DHCP Server
Alvarion BreezeNET B130/B300 GigE 223 Operational User Manual
4.16.1.7 Address Time
Any IP-address lease is limited by the time specified in Address Time option. If a
client which was given a lease does not extend it within Address Time period, the
server will cancel the lease. The value of this time may be defined by the client but
it should not exceed its maximal value. The maximal time of a lease is set up in
Address Time of one of the divisions to which this client is applied. If a server does
not have this option defined, the maximal time will be set to 120 seconds. In case
if a client does not request Address Time parameter, the server will give a lease for
a maximal time according to the scheme described above.
A client who received a lease, confirms it periodically. The periodicity is usually
equal to the half of Address Time. As an acknowledgement to the lease
prolongation the server resends configuration parameters (options). Thus, if
during the lease some of the options were changed in the server (or division to
which this client was applied) the client will learn it in the moment of lease
prolongation.
If after lease expiration the client does not confirm it, the scope cancels the lease.
If the client is not a scope reservation client, the scope will mark the IP-address of
this lease as "conditionally free". On scope state output (dhcpd show scope *) this
state will be marked as <OBIND>. Thus, with other addresses available for lease,
the scope will not give <OBIND> addresses for new clients. If during 24 hours
from the moment of lease expiration the client will request for a lease again, the
server will give him the same IP-address.
#1> dhcpd show scope MSOFT
>SCOPES:
(MSOFT) 192.168.177.20 - 192.168.177.22 [eth0]
ATTACHED [eth0] <192.168.177.12>/255.255.255.0
<CLIENT CLASS IDs>: "BRI_GATEWAY" "MSFT 5.0"
<CLIENT> ID:01:00:C0:DF:10:AF:69 "MSFT 5.0" 'wad '
192.168.177.20 <BOUND> since 01/01/2003 01:01:14
<O_BIND> ID:01:00:0F:EA:05:29:C6 "MSFT 5.0" 'win2k3sbs'
192.168.177.21 <OBIND>
<FREE RANGE> 192.168.177.22 - 192.168.177.22 =1
OK
At the same time, the scope writes down the parameters of expired lease into a
special database (boundhistory).
#1> dhcpd interface eth0 show boundhistory