Client is not issuing DHCP Release message after the specified Lease time???????

Simon Hobson dhcp1 at
Mon Dec 12 18:51:32 UTC 2011

ameen.shajahan at wrote:

>In dhcpd.conf file , i have done some changes.
>In that conf file,
>default lease time 3600;
>max-lease-time  7200;
>and i have changed to
>default lease time 10;
>max-lease-time  20;

Even for testing, 10 or 20s is a bit short.

>After the mentioned 20 seconds, Client is not sending DHCP release 
>message, Instead its again start sending Message from the beginning 
>like discover,offer,request,Ack.
>My problem is client not sending DHCP release message after the 
>(max-lease-time 20).

It's not required to. The fact that the lease end time is sufficient 
for both sides to know that the lease has expired.
DHCP-Release is used by a client that wants to explicitly end a lease 
it no longer needs, before it's due end time. Some clients will do 
this when the user tells them to shut down or sleep, most don't.

Also, you have sent this question to the BIND users list as well as 
the DHCP users list. That is very bad etiquette, the query has no 
connection whatsoever with BIND and you really should not clutter 
lists with irrelevant noise like that.

Simon Hobson

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author Gladys Hobson. Novels - poetry - short stories - ideal as
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