DHCP Based on MAC address

[nodeel]

heres a doozy.


We currently have a Linux machine that handles DHCP based ONLY on MAC address. So, a user who wants access to our network gives us their MAC address, we add it to the list, and restart DHCPd, and away he goes.


NOW, unfortunately, we're moving to an all MS Win2k Advanced Server (our director mandated this change, not me....grr)...


I've been unable to find a way to use Win2k Advanced Servers DHCP to base leases for IP addresses by MAC address. I know you can "reserve" ips based on Mac address, buts thats not what i want, as the users we have are very fluid....they disappear for months and I dont want them hogging up an IP address.


is there a way for Win2k's built in dhcp utility OR A THIRD PARTY UTILITY (provide linkage if you know of one) that can handle DHCP duties based on MAC address?

So, heres what i'd like:

We have a "pool" of IPs that are assigned via DHCP, but ONLY to users on a dedicated MAC address list. ALl other users are either forced to use static IPs or locked out of the network altogether.


Any help is appreciated.

Thanks!

 

[Jhereg]

You can create reservations based on MAC. Im not sure if this is what you are after though...

In the DHCP snap in right click the Reservation folder and enter the info ..

If your biggest fear is that some machines will hold an address "hostage" for months, then make the lease period only one day.

 

[Abzstrak]

sorry man, I understand what U want, and I really dont know of any way to do it with windows... there may be a 3rd party dhcp server that can, but I dont know of any.

Good reason to keep linux, if windows is completely incapable of something you need ;-) dunno how that will fly with the suits though

 

[nodeel]

yeah, the hostage IP is the main reason we're not giving IP reservations.


We have users go away for months (Sabatticals and such) and then we run out of DHCP ips because they never told us that that were leaving and we needed to remove them from our reservation list.

Thats why we liked the Linux solution so much.....basically to use DHCP, they need to provide us MAC address.


now i need to find a third party DHCP solution for Win2k.....any suggestions?

 

[Saltin]

<< Thats why we liked the Linux solution so much.....basically to use DHCP, they need to provide us MAC address >>



I don't understand how that fixes your "hostage IP" situation though. As suggested earlier, why dont you just make the lease duration shorter!?

You're not going to get great results from any form of DHCP in a 2k environment unless it's 2k or BIND.

 

[Nothinman]

I don't understand how that fixes your "hostage IP" situation though

As I understand it, they have a list of MAC addresses that can get IPs, so as long as you have a MAC address you submited to them you get to lease an IP, not a specific one.

 

[Saltin]

<< As I understand it, they have a list of MAC addresses that can get IPs, so as long as you have a MAC address you submited to them you get to lease an IP, not a specific one. >>



That much I know.

How does this help the problem he has though?



<< We have users go away for months (Sabatticals and such) and then we run out of DHCP ips because they never told us that that were leaving and we needed to remove them from our reservation list. >>



Not having a reservation list at all, and a shorter lease period would solve this problem.

He says he doesnt want to use 2k DHCP , but it's right up his alley far as I can tell. Am I missing something?

 

[Nothinman]

How does this help the problem he has though?

The problem is in Windows DHCP you can reserve an IP to a MAC address, but noone else gets that IP so it ends up useless if that person is away for some reason, that's the problem. With Linux right now they have a list of MACs that are allowed any IP, the rest can't get a lease.

Not having a reservation list at all, and a shorter lease period would solve this problem.

But not the problem of only allowing registered (by providing his dept with a MAC address) boxes to get IP leases.

 

[SaigonK]

The problem is in Windows DHCP you can reserve an IP to a MAC address, but noone else gets that IP so it ends up useless if that person is away for some reason, that's the problem. With Linux right now they have a list of MACs that are allowed any IP, the rest can't get a lease.

Are all your systems setup this way ?
I would figure out just how many people you think will be coming in and out and then assign them a specific address.
I mean realistically you cant have THAT many people coming in and out that you would run out of Ip's in a day.
Remember you have 250+ addresses, if you dont have 250 people leaving and not telling you then i dont see the problem....


But not the problem of only allowing registered (by providing his dept with a MAC address) boxes to get IP leases.


Mac address registration is frankly a joke, anyone can spoof an address if they need it, is your site that open to the public that you have people dropping in and
grabbing IP's all day? If so, think about a lock for the front door instead of a MAC based Ip security scheme.

 

[nodeel]

We have a dual network going.


We have around 250 IP's, 200 users are using static because they're permanent workstations in the building. We also have around 150 users howerever, are users that roam, bring laptops, bring their home computer, etc, and those ppl we provide access to our network by registering their machine's MAC address. The linux DHCP Server then gives them an IP via DHCP and away they go. We cant deal with all the administrative chores or IP reservations, as it would require a person about 5-10 hours a week to manage all the requiets. We OVERBOOK the DHCP network on purpose, because only 50 of the registered MAC address users are in at any given time...and thats on a crowded day.

Now that we know windows inherant DHCP server cant handle htis, anyone know of a good DHCP Server thats 3rd party and is better??

 

[manly]

Well the real problem is the PHB.

Any chance in hell he'll listen to the situation, and understand that Linux DHCP is the solution to keep?

 

[Abzstrak]

My vote is keep linux for at least doing the things that windows is incapable of natively. Using 3rd party programs on windows is not always the most stable method, especially not if its something minor like a dhcp server.... I mean if it was oracle or something, that would be different.

Whoever the bonehead is that is closed minded enough to think that windows can do everything needs some educating. I would suggest either yourself or a coworker... get someone with good speaking and arguing skills, not someone who will tick him/her off, but rather will reason with him and allow him to see the light.

Simply put, different OS's are better at different things, linux is a fantastic server OS and is EXTREMELY customizable. U have found one of the many things that is easy to do in linux, but difficult/impossible in windows, this is a good reason to run linux as a server.

 

[nodeel]

none the less.


Anyone know of any good third Party DHCP Servers that can run on win2k ?

 

[Woodchuck2000]

Why are you worried about only people who sumbit their MACs getting IP addresses? If it's a security issue, you could set up a MAC address based V-LAN to prevent any unauthorised users seeing people on your network...