[K12OSN] dhcpd.conf trouble

Eric Harrison eharrison at mail.mesd.k12.or.us
Fri Nov 4 20:43:50 UTC 2005

On Fri, 4 Nov 2005, Julius Szelagiewicz wrote:

> On Fri, 4 Nov 2005, Les Mikesell wrote:
>> On Fri, 2005-11-04 at 12:53, Julius Szelagiewicz wrote:
>>> P.S. If you know of a good tutorial on VLANs, please send me a link, I
>>> must have been dozing off when that was covered :-)
>> VLANs basically add a small header around the normal ethernet header
>> to tag packets so they can be isolated.  Sometimes the router/switch
>> equipment does all of the management, exposing only a single VLAN
>> on each connection; sometimes you use a trunk connection to other
>> vlan-aware equipment which then can appear to have multiple virtual
>> interfaces fron the single physical connection.  I don't think it
>> is documented very well but Linux is supposed to be able to handle
>> vlan trunks and sub-interfaces.  But, the point of running the phones
>> on a different VLAN would be to isolate the traffic physically so
>> in this case you probably want the switch or router to do it instead
>> of carrying them over to the server on the same trunk.
> Les,
> 	yes it is my preference to run the phones on a separate physical
> segment, but it is not an option. The switch is going in today/tomorrow
> and I have to use existing cabling, so the PCs and terminals will attach
> to ethernet ports on the phones. The VLAN "thing" according to the Mitel
> docs would work somewhat like this:
> 1. the phone gets dhcp address on VLAN 1 (my current real segment)
> 192.168.30.x
> 2. the phone talks to Mitel switch on VLAN 1, gets from it an address on
> VLAN 2 (192.168.31.x)
> 3. the phone releases address on VLAN 1
> 4. PC gets an address on VLAN 1
> I am a bit lost here since I have "missed" the material on VLANs and I am
> in NJ, the Mitel switch is in TX and I can't get there before Sunday. It
> all needs to work by Monday morning - the old phone setup has cratered, so
> I'm getting a new toy and the Company moves to IP phones.
> I need to know what to do about VLANs on my HP Procurve switches - not too
> hard according to the manuals and what to do about routing between VLANs.
> It should be easy, since the whole ball of wax is run on a K12Ltsp server,
> but I'm missing some crucial bits here.
> julius

Here is a revised sample dhcp.conf that should meet your needs... assuming
that the Mitel kit is providing DHCP on VLAN 2 and your K12LTSP server
is providing DHCP on VLAN 1 (that's how my school district is setup).

         option option-130 code 130 = text;
         option option-132 code 132 = string;
         option option-133 code 133 = string;

         subnet netmask {
                 default-lease-time 86400;
                 max-lease-time 864000;
                 option routers;
                 option subnet-mask;
                 if (option vendor-class-identifier = null) {
                         option option-130 "MITEL IP PHONE";
                         option option-132 0000:0000:0000:0002;
                         option option-133 0000:0000:0000:0005;


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