Quick update: as we’ve announced in this post just now: https://opensprinkler.com/forums/topic/announcing-opensprinkler-unified-firmware-2-1-5-major-bug-fix/, a major DHCP bug was discovered today, which explains the DHCP issues you’ve seen. The symptom occurs when you have DHCP reservation set up for OpenSprinkler (e.g. DHCP lease time is infinity). This triggers the bug and causes the controller to repeated send DHCP requests. The bug is now fixed. Hopefully it has addressed some of the issues users have encountered here.