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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>I have seen a few devices that consistently ignore DHCPOFFER messages. After some tinkering with standards compliant permutations of offers that they might not handle properly (e.g. lease times and RFC6842 client-id options), I got frustrated enough to try some standards non-compliant possibilities. It seems that despite requesting a broadcast response, they actually only receive and/or accept the DHCP message if it is unicast.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I tested this by creating a “–dhcp-unicast” configuration option that is identical to the “–dhcp-broadcast” option but with the exact opposite meaning, namely regardless of what the client asks for, use L2 unicast responses. With that change the devices (some Honewell thermostats and Sony TVs) started working.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Has anyone else seen problems like this? When I search on Honeywell Lyric thermostat Wifi connection issues, it does seem like a lot of people have undiagnosed problems with them, so this may be the cause.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Has anyone else seen devices that don’t seem to respond to DHCPOFFER messages? If so, do the corresponding DHCPDISCOVER messages have the broadcast bit set?<o:p></o:p></p></div></body></html>