[Cialug] DHCP question - Vendor info.

[Nathan C. Smith]

It is my understanding that when a system initiates a DHCP request it sends along a special code for vendor information.  In dhcpd, with use of a special conditional statement, you are supposed to be able to assign addresses based on this vendor specific information.

So my question is, short of actually sniffing the wire, is there a way to get the vendor-code that is sent?  Could it be located in a log file somewhere?  I don't see it in my DHCP logs but maybe I need to enable more detail?  I've also searched Google and found codes for some hardware and different versions of Windows.

My issue is this: I use DHCPD to assign static IP addresses based on all my known MAC addresses.  Any new addresses go into a special range.  Between this special range and arpwatch I can see new devices and unwelcome visitors on my network.  Since the VPN creates a special MAC address for each connection the addresses always go into the special range and create an arpwatch alert.  I'd like to be able to use the vendor info to place vpn users into a trusted range and really lock down the untrusted or visitor range.

If anyone can shed more light on the vendor info field in a DHCP request I would really appreciate it.  Thanks.

-Nate