Retaining information between DHCP requests

CLOSE Dave Dave.Close at
Thu Oct 9 16:17:48 UTC 2014

Simon Hobson wrote:

>> The DISCOVER and REQUEST messages in the first exchange include a
>> unique vendor-class-identifier starting with "anaconda". I can and
>> do detect that string and provide the special nameserver response
>> needed. But the subsequent REQUESTs do not include that string and
>> dhcpd then provides the normal operation response. That confuses
>> kickstart and the installation fails.

> The first suggestion is to look at why Kickstart isn't behaving
> properly - raise it as a bug report and see what happens.

I may do that. But even if the report is accepted and fixed, the time 
frame doesn't help me. I need to install machines now.

> Otherwise there are a few things I can think of.
> 1) Do you actually *have* to use a static address ?


> 2) Does the address used by kickstart have to be in the same range as
> that used by the machine once it's running ?

No. But once I add the entry to dhcpd.conf using "hardware ethernet", 
how do I then specify a different address for kickstart? Please recall 
that, in addition to an initial installation, I need to provide for a 
subsequent re-installation at any time, preferably without the need to 
edit dhcpd.conf at that time.

> 3) Would reserved leases help ?

Don't know.

> 4) Are you providing any "per host" options ?


> One thought is to use a separate pool for Kickstart. Use a class to
> have Kickstart use this pool and the booted machine to use the main
> pool. You can then apply options to the pools. If you *must* have
> fixed addresses, then would reserved addresses do ? Create a "stub"
> lease and add the "reserved" statement to it. That lease will then
> only be used for the specific client. Without the reserved statement,
> the addresses will still be effectively static if your set of
> machines is smaller than the pool size - because the server will try
> and issue the same address to each client even if it was long
> expired.

Basically, that's what I was trying to do using vendor-class-identifer, 
use a separate set of instructions for kickstart. I wasn't trying a 
different pool but that might be possible. Can you please enlighten me 
on how I can accomplish that?
Dave Close

More information about the dhcp-users mailing list