DHCP Server Leasing Addresses to MAC Addresses of 00-00-00-00-00-00

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I'm using a Draytek DSL Modem/Router which is acting as a DHCP server.
From this connections are made to a Linksys WRT54G and a separate
Click to expand...

connection to Server 2003 with a dual-NIC setup for hosting XP clients.
I also have Server 2003 as a DHCP server for a specific subnet of XP
clients that are internal to the business. I also have separate
connections from the modem/router that go to a Linux box and still more
connections to external client computers. Now when I connect the
client computers I'd like the DHCP server to lease them an address but
as you can see in the following log, the server gives out every
available lease after a short amount of time. In order to clear the
active DHCP sessions I have to reboot the server; then I can lease an
address to a client computer (as you can see by the second leased
address with the Host ID. After a few hours though the list looks like
below.

Any ideas on what's going on?

Any ideas on maybe a better group to post this to?

DHCP server: Running
Index IP Address MAC Address Leased Time HOST ID
1 192.168.1.1 00-50-75-1E-63-60 ROUTER IP
2 192.168.1.210 00-15-F3-9B-FA-34 0:13:57.340
Client-Desktop
3 192.168.1.211 00-00-00-00-00-00 0:20:40.390
4 192.168.1.212 00-00-00-00-00-00 0:20:40.440
5 192.168.1.213 00-00-00-00-00-00 0:20:42.380
6 192.168.1.214 00-00-00-00-00-00 0:20:42.430
7 192.168.1.215 00-00-00-00-00-00 1:20:44.520
8 192.168.1.216 00-00-00-00-00-00 1:20:44.570
9 192.168.1.217 00-00-00-00-00-00 1:20:46.500
10 192.168.1.218 00-00-00-00-00-00 1:20:46.550
11 192.168.1.219 00-00-00-00-00-00 2:20:48.390
12 192.168.1.220 00-00-00-00-00-00 2:20:48.440
13 192.168.1.221 00-00-00-00-00-00 2:20:50.390
14 192.168.1.222 00-00-00-00-00-00 2:20:50.440
15 192.168.1.223 00-00-00-00-00-00 3:20:52.380
16 192.168.1.224 00-00-00-00-00-00 3:20:52.430
17 192.168.1.225 00-00-00-00-00-00 3:20:54.380
18 192.168.1.226 00-00-00-00-00-00 3:20:54.430
19 192.168.1.227 00-00-00-00-00-00 4:20:56.400
20 192.168.1.228 00-00-00-00-00-00 4:20:56.450
21 192.168.1.229 00-00-00-00-00-00 4:20:58.410
 
"nomorespameventhoughthejapanesespamgivesmeachuckle"
I'm using a Draytek DSL Modem/Router which is acting as a DHCP server.

connection to Server 2003 with a dual-NIC setup for hosting XP clients.
I also have Server 2003 as a DHCP server for a specific subnet of XP
clients that are internal to the business. I also have separate
connections from the modem/router that go to a Linux box and still more
connections to external client computers. Now when I connect the
client computers I'd like the DHCP server to lease them an address but
as you can see in the following log, the server gives out every
available lease after a short amount of time. In order to clear the
active DHCP sessions I have to reboot the server; then I can lease an
address to a client computer (as you can see by the second leased
address with the Host ID. After a few hours though the list looks like
below.

Any ideas on what's going on?

Any ideas on maybe a better group to post this to?

DHCP server: Running
Index IP Address MAC Address Leased Time HOST ID
1 192.168.1.1 00-50-75-1E-63-60 ROUTER IP
2 192.168.1.210 00-15-F3-9B-FA-34 0:13:57.340
Client-Desktop
3 192.168.1.211 00-00-00-00-00-00 0:20:40.390
4 192.168.1.212 00-00-00-00-00-00 0:20:40.440
5 192.168.1.213 00-00-00-00-00-00 0:20:42.380
6 192.168.1.214 00-00-00-00-00-00 0:20:42.430
7 192.168.1.215 00-00-00-00-00-00 1:20:44.520
8 192.168.1.216 00-00-00-00-00-00 1:20:44.570
9 192.168.1.217 00-00-00-00-00-00 1:20:46.500
10 192.168.1.218 00-00-00-00-00-00 1:20:46.550
11 192.168.1.219 00-00-00-00-00-00 2:20:48.390
12 192.168.1.220 00-00-00-00-00-00 2:20:48.440
13 192.168.1.221 00-00-00-00-00-00 2:20:50.390
14 192.168.1.222 00-00-00-00-00-00 2:20:50.440
15 192.168.1.223 00-00-00-00-00-00 3:20:52.380
16 192.168.1.224 00-00-00-00-00-00 3:20:52.430
17 192.168.1.225 00-00-00-00-00-00 3:20:54.380
18 192.168.1.226 00-00-00-00-00-00 3:20:54.430
19 192.168.1.227 00-00-00-00-00-00 4:20:56.400
20 192.168.1.228 00-00-00-00-00-00 4:20:56.450
21 192.168.1.229 00-00-00-00-00-00 4:20:58.410
Click to expand...

You have a defective NIC on your network someplace, or a damaged driver.
(Drivers let you specify your own MAC in their configuration).

If that's not the case, then you have some rogue software on a PC someplace
making all these requests. At least the requests happen on a schedule and
you can disconnect PC's from the network one at a time to find the offender.
 
"nomorespameventhoughthejapanesespamgivesmeachuckle"


You have a defective NIC on your network someplace, or a damaged
driver. (Drivers let you specify your own MAC in their
configuration).

If that's not the case, then you have some rogue software on a PC
someplace making all these requests. At least the requests happen on
a schedule and you can disconnect PC's from the network one at a
time to find the offender.
Click to expand...

Is 00-00-00-00-00-00 even a legal MAC address? If not then I would
question the router for giving out a lease to that MAC address.

Another question I have is, how does DHCP work with regard to multiple
IP addresses for the same MAC? Should the DHCP server be releasing the
old IP when the same NIC requests a new IP or is there a different
mechanism for requesting multiple IPs vs. renewing the IP? I ask this
because, though I can give my NICs multiple static IPs, I don't see how
to get multiple dynamic IPs (but maybe this is just another Windows
shortcoming).
 
Another question I have is, how does DHCP work with regard to multiple
IP addresses for the same MAC? Should the DHCP server be releasing the
old IP when the same NIC requests a new IP or is there a different
mechanism for requesting multiple IPs vs. renewing the IP? I ask this
because, though I can give my NICs multiple static IPs, I don't see how
to get multiple dynamic IPs (but maybe this is just another Windows
shortcoming).
Click to expand...

In answer to my own question, apparently this is done by using a client
identifier other than the MAC address. As long as the client id is unique
to the subnet it's all legal.
 
Noozer said:
"nomorespameventhoughthejapanesespamgivesmeachuckle"


You have a defective NIC on your network someplace, or a damaged driver.
(Drivers let you specify your own MAC in their configuration).

If that's not the case, then you have some rogue software on a PC someplace
making all these requests. At least the requests happen on a schedule and
you can disconnect PC's from the network one at a time to find the offender.
Click to expand...

Thanks for the clues... I've narrowed it down to Server 2003 causing
the problem. I have yet to check if it is the NIC causing it or if
it's software related. Thanks again!
 
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