randomly(!) assign ip's from dynamic address range

[Mark Sandrock]

> On Jun 5, 2015, at 2:28 PM, Alex Bligh <alex at alex.org.uk> wrote:
> 
> 
>> On 5 Jun 2015, at 15:05, Simon Hobson <dhcp1 at thehobsons.co.uk> wrote:
>> 
>> Hmm, that's a variation I don't think we've seen before ;-)
>> What you are seeing is correct operation according to the RFCs - the server is required to keep the address stable as far as is possible, and that means the client can come back after an arbitrary length of time and as long as the address has not been re-used then the client *must* get the same address.
>> With the ISC server, addresses are allocated in the following order :
>> - The address the client had previously if it is still available
>> - An address which has never been issued before
>> - An expired lease, picking the least recently used one
>> - If there are no free leases available, then any abandoned leases are recovered and tried
>> - Else - there isn't one, log "no free leases"
> 
> In practice isn't the first address allocated the one the client asks for? IE normally the client is getting
> the same address because the client requests it, and it's free.
> 
I'm not sure about the client, but the
DHCP server stores the last client
to have had each address, and will
hand back that same IP even if the
client doesn't request it.

Modulo lease scavenging on Infoblox,
which as far as I know is running stock
ISC DHCP 4.2.4.

The client is probably only going to know
the last IP it had, which well could be
on an entirely different subnet, right?

Mark