Why do my local network ip addresses keep changing?

[Eric Shubert]

Yes, it's called a lease.
See http://www.ipcop.org/1.4.0/en/admin/html/services.html#services_dhcp 
for a look at how DHCP services are configured on IPCop. You can scroll 
down a little for the part pertaining to fixed leases.

Tim Bogart wrote:
> I could be wrong about it being called a license.  On second thought, I 
> think it's called a "lease."
> 
> t
> 
> ------------------------------------------------------------------------
> *From:* Tim Bogart <timbogart at yahoo.com>
> *To:* Main PLUG discussion list <plug-discuss at lists.plug.phoenix.az.us>
> *Sent:* Fri, October 1, 2010 9:40:41 PM
> *Subject:* Re: Why do my local network ip addresses keep changing?
> 
> Brian is absolutely right and I concur 100%.  However, more to your 
> question, Joe,  They might change addresses once in a while because they 
> are inactive for a time and which ever box is acting as your dhcp server 
> is putting that address back in to the pool of available IP addresses. 
>  Normally, dhcp will see the mac address of your network interface card 
> (nic) and see if your previous address is available and if it is, will 
> issue it to that machine again.  The duration of the time an ip address 
> will be assigned to any particular machine is determined by a 
> programmable variable called the "license".  The administrator is the 
> one who determines this duration.  Normally it's a matter of da ys. 
>  Usually three days is the shortest.  The longest? Who knows.  It's up 
> to the administrator.  But that's why they are changing on you.  Again, 
> unless you have a small IP address pool available to you, which you do 
> not if you are using a private ip range as stated in the RFC's that 
> pertain to TCP/IP and dhcp, then just go into your network settings, set 
> them to static, lean back and cruise.  Then they will never mysteriously 
> change on you again.  They will remain the same for ever and ever and 
> ever...etc...etc.
> 
> Tim
> 
> ------------------------------------------------------------------------
> *From:* Brian Cluff <brian at snaptek.com>
> *To:* Main PLUG discussion list <plug-discuss at lists.plug.phoenix.az.us>
> *Sent:* Fri, October 1, 2010 9:23:11 PM
> *Subject:* Re: Why do my local network ip addresses keep changing?
> 
> DHCP usually tries to keep the same IP address if possible, so unless
> you have more computers than you have IP addresses available, my guess
> would be that you have second DHCP server handing out IP addresses and
> your computers are bouncing back and forth between the one you mean to
> use and the rogue DHCP server.
> 
> Brian Cluff
> 
> On 10/01/2010 05:04 PM, joe at actionline.com <mailto:joe at actionline.com> 
> wrote:
>  >
>  > I have four computers on my local network, 3 of which access by wireless.
>  > While most will go along working fine for a while, occasionally the ip
>  > number changes on some of them.
>  >
>  > Why does that happen and is there any way to prevent that or t o be 
> able to
>  > reset the ip# back to what it was?
>  >


-- 
-Eric 'shubes'