Best practice for defining static IP addresses?

[Shawn Holland]

Hi,

I have read the link in this thread and it is the same scenario I have.
However, the only requirement I have different is that I need a DHCPNAK
to be sent out.

My dhcpd.conf has:

         subnet 10.250.15.0 netmask 255.255.255.0 {
                pool {
                        deny unknown-clients;
                        range 10.250.15.2 10.250.15.254;
                        option domain-name-servers 10.250.15.1;
                        option dhcp-server-identifier 10.250.15.1;
                        option routers 10.250.15.1;
                        default-lease-time 600;
                        max-lease-time 1200;
                }
        }

I have host declarations:

host 001B9E8A711A {
        hardware ethernet 00:1B:9E:8A:71:1A;
        fixed-address 10.250.15.2;
}

However I want to be able to remove that declaration at any time,
restart dhcpd and have the pool send a DHCPNAK so the client will do a
new DHCPDISCOVER.

As of right now if I set it up properly and exclude the 10.250.15.2
address from the pool range it does not send a DHCPNAK to the client
that does a DHCPREQUEST for 10.250.15.2.

The reason is I have a default pool I want them to fail over to if their
static host entry is removed.

Any help would be appreciated.

--
Shawn

On Wed, 2008-08-06 at 14:08 -0500, Ryan McCain wrote:
> Todd,
> 
> Thanks for the link.
> 
> >>> On Wed, Aug 6, 2008 at  9:45 AM, in message
> <1D8C9A4471119A40BD574F9D8D464AE301B85A76 at XCH60YKF.rim.net>, "Todd Snyder"
> <tsnyder at rim.com> wrote: 
> > http://marc.info/?l=dhcp-users&m=121088413725977&w=2 Covers it I think
> > 
> > Cheers,
> > 
> > Todd.
> > 
> > -----Original Message-----
> > From: dhcp-users-bounce at isc.org [mailto:dhcp-users-bounce at isc.org] On
> > Behalf Of Ryan McCain
> > Sent: Wednesday, August 06, 2008 10:24 AM
> > To: dhcp-users at isc.org
> > Subject: RE: Best practice for defining static IP addresses?
> > 
> > Todd,
> > 
> > Thanks for the info.  Do you have a link to your thread?
> > 
> > 
> >>>> On Tue, Aug 5, 2008 at  4:02 PM, in message
> > <1D8C9A4471119A40BD574F9D8D464AE301B85A6C at XCH60YKF.rim.net>, "Todd
> > Snyder"
> > <tsnyder at rim.com> wrote:
> >> I thought this very same thing until a few months ago, and after
> >> bashing my head about for a while, I came here and was corrected.
> >>
> >> Static assignments need to be outside any defined ranges.  This is
> >> different than Windows DHCP, which lets you 'reserve' an ip in the
> >> middle of range.
> >>
> >> If you want to do the first option, you will have to define 2 ranges
> >>
> >> range 10.119.14.1 10.119.14.99
> >>
> >> and
> >>
> >> range 10.119.14.101 10.199.14.179
> >>
> >> Which isn't ideal.
> >>
> >> Cheers,
> >>
> >> Todd.
> >>
> >> -----Original Message-----
> >> From: dhcp-users-bounce at isc.org [mailto:dhcp-users-bounce at isc.org] On
> >> Behalf Of Ryan McCain
> >> Sent: Tuesday, August 05, 2008 4:55 PM
> >> To: dhcp-users at isc.org
> >> Subject: Best practice for defining static IP addresses?
> >>
> >> Lets assume this is my DHCP scope:
> >>
> >> subnet 10.119.14.0 netmask 255.255.255.0 {
> >>   range 10.119.14.1 10.119.14.179 ;
> >>   option routers 10.119.14.254 ;
> >>
> >> If I wanted to assign a static IP address, would I do?
> >>
> >> host Black {
> >>   hardware ethernet 00:19:5B:EC:A7:11;
> >>   fixed-address 10.119.14.100;
> >> }
> >>
> >> or
> >>
> >> host Heart {
> >>   hardware ethernet 00:19:5B:EC:A7:12;
> >>   fixed-address 10.119.14.200;
> >> }
> >>
> >> ..Notice that 'Black' is within the defined range while 'Heart' is
> > not.
> >>
> >> I've always assume I could assign a static IP within the defined range
> > 
> >> and the MAC address would act as a 'key' to prevent it from being
> >> handed out  (even though it's in a defined range).
> >>
> >> Thanks for the clarification..
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> ---------------------------------------------------------------------
> >> This transmission (including any attachments) may contain confidential
> > 
> >> information, privileged material (including material protected by the
> >> solicitor-client or other applicable privileges), or constitute
> >> non-public information. Any use of this information by anyone other
> >> than the intended recipient is prohibited. If you have received this
> >> transmission in error, please immediately reply to the sender and
> >> delete this information from your system. Use, dissemination,
> >> distribution, or reproduction of this transmission by unintended
> > recipients is not authorized and may be unlawful.
> > 
> > 
> > 
> > ---------------------------------------------------------------------
> > This transmission (including any attachments) may contain confidential 
> > information, privileged material (including material protected by the 
> > solicitor-client or other applicable privileges), or constitute non-public 
> > information. Any use of this information by anyone other than the intended 
> > recipient is prohibited. If you have received this transmission in error, 
> > please immediately reply to the sender and delete this information from your 
> > system. Use, dissemination, distribution, or reproduction of this 
> > transmission by unintended recipients is not authorized and may be unlawful.
> 
>