one-lease-per-client... seriously

Brian Rak brak at
Thu Sep 15 20:00:14 UTC 2016

I'm running into an issue where DHCPD (v4.3.4 and older versions) is 
issuing multiple leases to the same mac address.  It appears to be 
looking at the DHCP Client-ID field to determine what a unique client 
is.  I'd much rather it ignore everything except for the client's mac 
address, but I can't seem to find an option to do this.

I already have:

one-lease-per-client                                    true;
deny duplicates;

in my config, which doesn't seem to be helping.

This is a problem, because I'm using DHCP for PXE booting, which means 
each machine ends up getting three concurrent leases:

one via the firmware built into the nic
iPXE then gets chainloaded, and gets another lease
the actual OS gets loaded, and gets a different lease

It's very difficult to get these all to share leases, and I'd really 
much rather handle this on the DHCP server side.  DNSMasq can do this, 
but it doesn't scale well enough.

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