> On 7 Aug 2017, at 07:34, Ola Thoresen <o...@nlogic.no> wrote:
> Technically, the server is correct in that after a "release" is received, it
> is free to assign the address to another client, and as such, the client
> should not expect to receive the same address on the next assignment.
> However, following the principle of least surprise, I agree that the user
> probably expects to receive the same address, especially if they are just
> changing some settings on the wan interface.
> If you are free to change both server and client behavior, I believe a
> combination of 2 and 4 is probably the "most correct" solution.
> The client should probably send a release both for v4 and v6 at the same
> But on the other hand, it would be nice if the server would remember the
> previous lease, at least for a while, and reassign it to the client if
> another request comes in within a reasonable time.
Yes, option 5 might be “2+4”. In options 2 & 5 to avoid a change in service
level for IPv4 the DHCP server would also need to remember the IPv4 lease for a
period long enough to keep the address the same after the Release followed
shortly afterwards by a Discover. That is a configuration option at my DHCP
server. The IPv4 pools, unlike the large IPv6 prefix pools, are run pretty hot
close to capacity to maximise the v4 pool utilisation.