Disabling Netbios over TCP/IP via DHCP does not work

Question

I'm working towards disabling Netbios over TCP/IP for my organization. I've created a reservation for my MAC address. I can see that the reservation becomes active when I renew my IP address. I set option 001 under the Microsoft Options vendor class and the Default BOOTP class with a value of 0x2. When I renew my IP address, the DHCP server never adds this option to the DHCP Offer or DHCP ACK.

How do I need to configure the options in order to get this functioning properly?

Solution

I believe the problem in my case was due to an incorrect User class being specified. I had run ipconfig /showclassid "Local Area Connection", which gave me the following output:

Windows IP Configuration

DHCPv4 Classes for Adapter "Local Area Connection":

   DHCPv4 ClassID Name . . . . . . . . : Default Routing and Remote Access Class
   DHCPv4 ClassID Description  . . . . : User class for remote access clients

   DHCPv4 ClassID Name . . . . . . . . : Default BOOTP Class
   DHCPv4 ClassID Description  . . . . : User class for BOOTP Clients

I thought, from this output, that I should have been using the Default BOOTP Class. After reconfiguring the options for the Default User Class, however, everything appears to be working now. Currently I have the option set in both the Microsoft Options vendor class as well as the Microsoft Windows 2000 vendor class.

It's interesting to note that a Wireshark capture still does not show the DHCP option being set. It seems that Wireshark displays this data under a Vendor-Specific Information "parent" option, but I can't be certain at this point.

Comments

[ravi yarlagadda]

Did you apply that option only to the specific reservation? Also, have you confirmed in the raw DHCP packets that the option isn't being set?

[Harry Johnston]

What DHCP server are you using?

[bshacklett]

Windows DHCP services.

[bshacklett]

Make that Windows 2003 DHCP services.

[bshacklett]

If no WINS servers are configured, Windows will fall back to broadcast resolution, which is not something I would like to experience with 2000 or so hosts on a network with multiple subnets.

[Harry Johnston]

There is definitely a DHCP option to control NetBIOS over TCP/IP on current Windows versions. We're using it here, although we have a Linux-based DHCP server.