Re: Kickstart http parameters

[Alf Wachsmann <alfw SLAC Stanford EDU>]

On Wed, 2 Apr 2003, John wrote:
> > On Wed, 2 Apr 2003, Tony Nugent wrote:
> > But in the end, wouldn't it be much easier to have a dhcpd server
> > allocate static IPs based on the HW address, then have the
> > host-specific ks.cfg file available based on IP rather than HW
> > addresses?  (This is the more traditional approach).
>
> As I've already pointed out, you cannot rely on MAC addresses unless you
> have the knowledge that the server and client are on the same piece of
> wire.

We are using static IP addresses and we fill our dhcpd.conf file via
a script that does SNMP queries to the switch the client nodes are
connected to.

This script reads out the MAC address and the port the switch sees it on.
Because I know our cabeling, I know which IP address is supposed to be
assigned to a particular host (= switch port).

I am using this mechanism in real time for new machines:
Machined does DHCP broadcast during PXE -> initializes switch port ->
fills switch CAM table -> SNMP read -> fill dhcpd.conf -> kick dhcp server
-> serve IP address to PXE client.

Oh, before you ask: the script works for Cisco 6509s only.
See http://www.slac.stanford.edu/~alfw/PXE-Kickstart/ for more details.

-- Alf.

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