Classifying traffic according to options passed in a host statement

[Brian Raaen]

I am trying to work with our cable modem provisioning system to set up a way 
that docsis 1.0, 1.1, and 2.0 would get the correct config files without 
having to be statically assigned.  Currently we provision cable modems using 
host statements like the following

host 0000cac6eb42 {filename "153651202sc.cfg"; hardware ethernet 
00:00:ca:c6:eb:42;}
host 000103B17FD6 {filename "51212802s.cfg";      hardware ethernet 
00:01:03:B1:7F:D6;}
	
I need to give it an option other than filename, that the server will use to 
evaluate the option.  I tried creating an option called modem-conf like the 
following

host 0000cac6eb42       {option modem-config "153651202sc.cfg"; hardware 
ethernet 00:00:ca:c6:eb:42;}
host 000103B17FD6       {option modem-config "51212802s.cfg";   hardware 
ethernet 00:01:03:B1:7F:D6;}

and then apply different configs in the subnet using the following code

if substring (option modem-config, 0, 15)  = "153651202sc.cfg" {

	if substring (option vendor-class-identifier, 0 , 9) = "docsis2.0" {
		filename = "153651202sc20.cfg";

	} else if substring (option vendor-class-identifier, 0 , 9) = "docsis1.1" {
		filename = "153651202sc11.cfg";

	} else {
		filename = "153651202sc10.cfg";

	}
}


however all the modems are getting the subnet default file. instead to getting 
the different speed files.  I am not sure how I can read the host options to 
make assignment decisions.  I would appreciate any help I can get.

-- 
Brian Raaen
Network Engineer
braaen at zcorum.com