dhcpd new leases Win98 machines

Hi all,

I'm attempting to move my dhcpd server from one box to another.

Is there a way to force windows machines to get a new ip address
from the new server? I am, or I'd like to, set up a new range
of ip numbers, but the win98 machines aren't cooperating.

Could anyone point me somewhere toward a clue?

I'm using Internet Systems Consortium DHCP Server V3.0.1
on a slackware box. My dhcpd.conf is:

authoritative;
max-lease-time 604800;
default-lease-time 86400;
option subnet-mask 255.255.255.0;
option domain-name "bozomania.com";
option domain-name-servers 192.168.2.7;
ddns-update-style interim;
subnet 192.168.2.0 netmask 255.255.255.0 {
range 192.168.2.130 192.168.2.160;
allow unknown-clients;
option routers 192.168.2.5;
option broadcast-address 192.168.2.255;
}

Thanks
--
Julien Mills Amoroso's Baking Company
Tel: (215) 471-4740 IS Dept
email: (E-Mail Removed) www.amorosobaking.com

julien mills <(E-Mail Removed)> wrote:
> Hi all,
>
> I'm attempting to move my dhcpd server from one box to another.
>
> Is there a way to force windows machines to get a new ip address
> from the new server? I am, or I'd like to, set up a new range

No, nor can you do that with any other client. It's simply not a capability
that the DHCP spec posseses.

A better solution would be to shut down the DHCP server, and then just make
sure you copy over the leases file. This means that the new server would
contain the same state information as the old one.

--
Frank Sweetser fs at wpi.edu | For every problem, there is a solution that
WPI Network Engineer | is simple, elegant, and wrong. - HL Mencken
GPG fingerprint = 6174 1257 129E 0D21 D8D4 E8A3 8E39 29E3 E2E8 8CEC

On 2005-08-02, Frank Sweetser <(E-Mail Removed)> wrote:

>> I'm attempting to move my dhcpd server from one box to another.
>>
>> Is there a way to force windows machines to get a new ip address
>> from the new server? I am, or I'd like to, set up a new range
>
> No, nor can you do that with any other client. It's simply not a capability
> that the DHCP spec posseses.

My linux boxes will accept a new ip address from the new box. They request
their old ip, but accept a new one.

> A better solution would be to shut down the DHCP server, and then just make
> sure you copy over the leases file. This means that the new server would
> contain the same state information as the old one.

OK, if I must, I guess I'll do that.

--
Julien Mills Amoroso's Baking Company
Tel: (215) 471-4740 IS Dept
email: (E-Mail Removed) www.amorosobaking.com

julien mills wrote:
> On 2005-08-02, Frank Sweetser <(E-Mail Removed)> wrote:
>
>
>>>I'm attempting to move my dhcpd server from one box to another.
>>>
>>>Is there a way to force windows machines to get a new ip address
>>>from the new server? I am, or I'd like to, set up a new range
>>
>>No, nor can you do that with any other client. It's simply not a capability
>>that the DHCP spec posseses.
>
>
> My linux boxes will accept a new ip address from the new box. They request
> their old ip, but accept a new one.
>
>
>>A better solution would be to shut down the DHCP server, and then just make
>>sure you copy over the leases file. This means that the new server would
>>contain the same state information as the old one.
>
>
> OK, if I must, I guess I'll do that.
>
Under newish windoze (at least NT4 and later) I seem to remember there
was IFCONFIG/RENEW from commandline which tries to renew the current
leases on all DHCP interfaces, and if the old DHCP server doesn't reply,
asks for a new address. Dunno if 98 had that already.

J.

In comp.os.linux.networking <(E-Mail Removed) m> julien mills <(E-Mail Removed)> wrote:
> Is there a way to force windows machines to get a new ip address
> from the new server? I am, or I'd like to, set up a new range
> of ip numbers, but the win98 machines aren't cooperating.

Remember that Win98 remembers the last lease it got, and tries to
contact the server it got it from first before looking for new
servers. If the old server's still running and handing out leases,
the Win98 machines will continue to look to it. You might be able
to force the issue with an explicit "ipconfig /release" and then
"ipconfig /renew", but more likely you'll have to shut down the
old server first and then either use those commands or let the
leases expire and the machines should start looking for new servers
automatically when the old one doesn't answer.

--
death.net: because for some problems there's only one solution.

julien mills <(E-Mail Removed)> wrote in
news:(E-Mail Removed). com:

> Hi all,
>
> I'm attempting to move my dhcpd server from one box to another.
>
> Is there a way to force windows machines to get a new ip address
> from the new server? I am, or I'd like to, set up a new range
> of ip numbers, but the win98 machines aren't cooperating.

The DHCP server is located by a broadcast. If two DHCP servers are
listening on your network and receive the DHCP request, I suppose they
will both try to reply. The one that replies first will win I suspect.
It may be possible to configure the DHCP software to explicity ignore
requests from certain MAC addresses?

Klazmon.

In article <(E-Mail Removed)> ,
julien mills <(E-Mail Removed)> wrote:
:Hi all,
:
:I'm attempting to move my dhcpd server from one box to another.
:
:Is there a way to force windows machines to get a new ip address
:from the new server? I am, or I'd like to, set up a new range
f ip numbers, but the win98 machines aren't cooperating.
:
:Could anyone point me somewhere toward a clue?

You can't make them do that immediately, but you can modify the current
server's config file with a very short lease time and an explicit
server-identifier statement pointing to the new server. See `man
dhcpd.conf` for details. The next time the client renews it will get
the short lease and renew again almost immediately -- this time with the
new server.

Whether the client machine deals gracefully with the change in its IP
address is another matter, and not within your control.

--
Bob Nichols AT comcast.net I am "rnichols42"

On 2005-08-02, Todd Knarr <(E-Mail Removed)> wrote:
>> Is there a way to force windows machines to get a new ip address
>> from the new server? I am, or I'd like to, set up a new range
>> of ip numbers, but the win98 machines aren't cooperating.
>
> Remember that Win98 remembers the last lease it got, and tries to
> contact the server it got it from first before looking for new
> servers. If the old server's still running and handing out leases,
> the Win98 machines will continue to look to it. You might be able
> to force the issue with an explicit "ipconfig /release" and then
> "ipconfig /renew", but more likely you'll have to shut down the
> old server first and then either use those commands or let the
> leases expire and the machines should start looking for new servers
> automatically when the old one doesn't answer.

Thanks everyone for the responses. I had already shut down the
old server and brought up the new one. What I didn't know
was the "ipconfig /release" and "ipconfig /renew" commands.

These allowed the win98 machine to get a new ip address, and it
was updated in named, finally. I just didn't expect it to work this
way.

--
Julien Mills Amoroso's Baking Company
Tel: (215) 471-4740 IS Dept
email: (E-Mail Removed) www.amorosobaking.com

In comp.os.linux.networking <(E-Mail Removed) m> julien mills <(E-Mail Removed)> wrote:
> These allowed the win98 machine to get a new ip address, and it
> was updated in named, finally. I just didn't expect it to work this
> way.

What may have happened is that the leases hadn't expired yet. A
DHCP client isn't supposed to go looking for a new lease until the
old one's expired _and_ the server it was obtained from refuses to
answer or denies the request. If the server doesn't answer but the
lease hasn't expired, the client's supposed to continue using the
IP under the existing lease until it expires. In Windows there's
no way other than the IPCONFIG commands to force it to forget the
lease and start over from scratch.

--
death.net: because for some problems there's only one solution.

On 2005-08-03, Todd Knarr <(E-Mail Removed)> wrote:
>> These allowed the win98 machine to get a new ip address, and it
>> was updated in named, finally. I just didn't expect it to work this
>> way.
>
> What may have happened is that the leases hadn't expired yet. A
> DHCP client isn't supposed to go looking for a new lease until the
> old one's expired _and_ the server it was obtained from refuses to
> answer or denies the request. If the server doesn't answer but the
> lease hasn't expired, the client's supposed to continue using the
> IP under the existing lease until it expires. In Windows there's
> no way other than the IPCONFIG commands to force it to forget the
> lease and start over from scratch.

Todd, thank you for that explanation which makes sense. So, what
I could do is shorten the lease time on the old server, so when
I turn it off, the leases will expire more quickly and they'll
renew on the new server. Or, I could just walk around the building
and force them to renew.

--
Julien Mills Amoroso's Baking Company
Tel: (215) 471-4740 IS Dept
email: (E-Mail Removed) www.amorosobaking.com