cannot change ip address in pool (fixed question)

Simon Hobson dhcp1 at
Fri Sep 14 15:48:52 UTC 2012

Jan nowak wrote:
>I think I fixed the problem. I changed two variables:
>default-lease-time 600; ( before 1200)
>max-lease-time 3600; ( before 12000)
>Is it good to have these values when i have more than 1k users ?

FFS - will you please learn how to trim what you're quoting - instead 
of quoting about 12k of irrelevant text for a 4 line message ! 
Failure to trim quoted material usually goes with top posting.

As to your question, you tell us.
There is no such thing as "right" or "wrong" - only what it "best 
compromise" for your situation.

Your values will mean that for devices which do not request a 
specific lease time, they will get a lease of 10 minutes duration 
which they will renew about every 5 minutes. If you have a DHCP 
failure, then clients will lose their leases and stop working roughly 
5 to 10 minutes later.
If a client requests a longer lease, then this rises to renewal every 
30 minutes, with connectivity lost between 30 and 60 minutes after 
loss of DHCP service.

The upside, and what you are relying on here, is that when a devices 
is swapped out, the old lease will expire within these times and then 
the new devices will be able to get a lease.

Simon Hobson

Visit for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
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