How to get UUID/GUID of a client

Simon Hobson dhcp1 at
Wed Feb 9 10:46:00 UTC 2011

Ben wrote:

>I try many options to get the UUID/GUID of a client in a boot 
>process, but no one return the UUID/GUID.
>I know that "hardware" option with "binary-to-ascii(10, 8, " :", 
>hardware)" function give the MAC address, but I also noticed that 
>"uid" option exists, but how to convert it to string?

If you look in the leases file you will see a field for client uid, 
it is a simple string with any non-printing octets escaped as octal 

>In fact, I would like to give a static IP address static by the 
>UUID/GUID, not by the MAC address.

That's not currently supported as a fixed-address statement. However, 
you could use the "reserved" qualifier to tie a lease to a specific 
client. If you know the UID in advance, then you can create a dummy 
lease with an IP address and UID - and adding "reserved". That will 
then reserve that address to only be used by a client with that uid - 
once the client boots, the dummy lease will be replaced with a real 
Alternatively, you can simply set the lease as reserved after the 
client has booted.

Setting reserved can be done by editing the lease file (after 
stopping the server), or I believe it can be done with OMAPI.

Simon Hobson

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