Question about dhcp-client-identifier

Darren perl-list at
Wed Aug 22 13:01:07 UTC 2007

> In both cases the devices will not work properly, wouldn't it be 
> better for them to be very broken so that the problem is less subtle 
> and less hard to diagnose ?
Yes - we would definitely like the clients to be completely broken - 
basically, we don't want there to be two devices with the same mac to be 
able to get two different ips, period!  It makes it awfully hard to 
figure out who had what ip address when if two people have the same mac 
and continue that way indefinitely.

> Also, I believe it's planned for a future version to allow the admin 
> to specify the key - so you could change it from the current (fixed) 
> setting of "pick first ( client_id, hardware)" to just "hardware".

This is ideal!  If we could specify to key on hardware, would that not 
force the DHCP server to do one of the following depending on condition:

1) if the two devices are in the same physical network, allocate them 
the same IP address thus causing them both to be in a broken state (so 
that one of them will need to modify their mac address).  I would expect 
this behavior on the same physical network as the DHCP server would not 
know the difference between the two client devices.

2) if the two devices are in separate physical networks, prevent one of 
them from obtaining an IP due to: one-lease-per-client true; setting.  I 
would expect this behavior as the DHCP server would see both as the same 
client and would deny an IP for one of the requests from the separate 

More information about the dhcp-users mailing list