To make patches persist across upgrades add the .deb to

     /config/data/firstboot/install-packages

This patch add's the ability to assign a persistant lease file

    file /config/dnsmasq-dhcp.leases

CLI example:

    uname@ubnt# set service dhcp-server lease-persist 
    Possible completions:
    enable	Enable persistant leases for dnsmasq
    disable	Disable persistant leases for dnsmasq (default)

NOTE:

• Supports all model's but only tested on ER-12
• This currently only works for dnsmasq
• There is logic added that will not overwrite the dnsmsaq-dhcp-config.pl file if ubnt made changes to it since the last version

TODO:

• add log messages on error's
• add dhcpd support