one-lease-per-client... seriously

Jeff Wieland wieland at
Thu Sep 15 20:33:15 UTC 2016

Brian Rak wrote:
> 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.
> _______________________________________________
> dhcp-users mailing list
> dhcp-users at
I've not used it, but it looks like the ignore-client-uids statement 
might work.

Jeff Wieland, UNIX/Network Systems Administrator
Purdue University IT Infrastructure Services UNIX Platforms

More information about the dhcp-users mailing list