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10.4: DHCP Static Maps on OS X 10.4 Server OS X Server
I was trying to figure out why Static Maps would not work on my 10.4 Server. The setup is straightforward: add MAC Address and assign IP; pretty simple. However, my server would not hand out the assign IPs.

Well I found out that when you create static maps on OS X Server, your clients should not have anything in the DHCP Client ID box (i.e. they should leave it blank). Hopes that helps someone!
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10.4: DHCP Static Maps on OS X 10.4 Server | 4 comments | Create New Account
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10.4: DHCP Static Maps on OS X 10.4 Server
Authored by: EricMc on Aug 07, '07 08:28:36AM

I've had mixed results from changing the client id in this case. It seems to be that if there is already an entry for the machine you are trying to statically assign an IP for, the DHCP server will use that regardless of the new assignment. Changing the client id can make the machine look like a different one from the perspective of the DHCP server.

The most reliable way I have found to make this work is to stop the DHCP server, edit dhcpd_leases in /var/db/ (as root or with sudo, of course), and then restart the DHCP server.

To edit the lease, just find the machine in question (you may have to hunt down its MAC address) and change the ip on the lease to the one you have statically assigned. There can be several instances in the file for a given machine. Just delete all but the one you have edited.

Just deleting the entry won't work because the client will send in its old IP when it renews and the DHCP server will accept this instead of using the static assignment.

After the DHCP server is back up, go to the client machine and click the renew DHCP button on the appropriate interface in the network preferences.

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10.4: DHCP Static Maps on OS X 10.4 Server
Authored by: gnunnery on Aug 07, '07 12:57:44PM

When the ClientID field contains an entry the client sends the hex value of that instead of the MAC address to the DHCP server when requesting service; unfortunately, this is not recognized.

I have not tried, but maybe it's possible to enter that hex data when configuring the server's Static Mapping instead. If so this would be recognized.

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10.4: DHCP Static Maps on OS X 10.4 Server
Authored by: nox on Aug 07, '07 11:46:42PM

In addition when adding a large amount of mac addresses to static maps. I recommend the following free programs.

Wake on Lan ( to harvest mac addresses / creates csv )
Static Mac Importer ( takes csv and imports into DHCP ).

Hope this helps.

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10.4: DHCP Static Maps on OS X 10.4 Server
Authored by: RobLewis on Aug 10, '07 12:36:53PM

I discovered this myself months ago after pulling out large quantities of hair. IIRC, you can specify EITHER the client's name or MAC address, but not both. (BTW, I think some 3rd party routers work the same way; I wonder if the RFCs say anything about this.)

The client name is an attractive option, since you can make sure a user always gets the same IP address even if they get a new computer.

Anyway, nice job, Apple, on the documentation and UI...NOT!

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