Classifying traffic according to options passed in a host statement

[Brian Raaen]

Dear Simon,
	Actually I do need to use host for two different reasons.  The first reason 
is that we have situations where we assign static ip addresses to the modems.  
The second reason is that my company required that my solution did not break 
the current framework that our provisioning software uses to add modem.  The 
program our software developers created writes the host statement to a 
modem.conf file where the modems are tracked.  I checked with the software 
guy and he said it may not be too difficult to modify the code to use 
something like 'option modem-conf' in the place of 'filename'.  I had thought 
of using groups, but that would require additional logic in the provisioning 
software. 

-- 
Brian Raaen
Network Engineer
braaen at zcorum.com

On Wednesday 24 October 2007 16:42, Simon Hobson wrote:
> Brian Raaen wrote:
> >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.
> 
> OK, do you NEED the host statements ?
> 
> Would the classes and subclasses by mac address example in the man 
> page (man dhcpd.conf) work for you ? Specifically, if all you use the 
> host statements for is to passing options (such as filename) to a 
> client, then this could be done through a class. For each client, you 
> specify which class it should be in, and it gets the options 
> specified in the class definition.
> 
> 
>