Extend IP Pool

[NiKiZe]

You might be able to add a filter so that this range is in a user-class iPXE or PXEClient vendor, and then maybe add a bunch of filters to have the correct range used.
But that is mostly just a bad solution.

Also remember that the DHCP server needs to have an IP in that range, or it should be called via dhcp-relay.
And finally do check the logs and explain in details what is not working.