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I have an ASUS RT-AC88U wireless router that provides DHCP services to all of my wired and wireless devices. It is dual-band and broadcasts at 5GHz and 2.4 GHz. I have a total of 17 devices connected to the Wifi router; 5 of them are on the 2.4GHz signal, others are either wired or 5GHz.
I have a Honeywell Vision Pro 8000 (TH8321WF) thermostat that can be connected to WiFi via the 2.4GHz signal. Thermostat Manual
I had two of these Honeywell thermostats successfully connected to my WiFi network for a few days. Later they became disconnected and I have been unable to re-connect them to the network. I've even received two new thermostats thinking that they may have been affected by an electrical short.
Each time I try to reconnect the thermostats, I end up getting an error message thats says, "Connection Failed The thermostat was unable to obtain an IP address from your network. Make sure that your network is configured to assign an IP address to this thermostat"
I've tried the following:
verified that the thermostat can connect to my cell phone's hotspot when the hotspot is active. (so the thermostat Wifi antenna works)
powering the thermostats down and back up.
rebooting my WiFi router.
updating my Wifi router firmware.
reset my Wifi router to factory settings
contacted Honeywell customer service; they sent a silly router configuration guide that made very little sense.
disabled the router firewall; still no luck, re-enabled
reviewed the router general and system logs to see if I could detect if DHCP was attempting to issue an IP address to the thermostat; I could not see any logs that suggested I could view ANY IP addresses being issued to any of my devices, but I could see current (successfully issued) IP addresses and when the lease would expire.
verified that the wifi signal near the thermostats is strong
My WiFi network is running both 2.4GHz and 5.GHz and WPA2 encryption - specifically, WPA2-Personal with AES encryption. The password to my firewall is 15 characters long with no special characters - only alpha-numeric.
Can someone provide me with some troubleshooting suggestions?
Are there other troubleshooting things I could be trying or observing?
Another forum suggested that I set up Wireshark, but I'd like to see if there is something else I could do before going to that level. Thanks
1You can try setting the Mac address in the routers DHCP server options to give them permanent IP addresses through dhcp. (If you have that option) another option would be to set the devices themselves to have static IP addresses outside of the DHCP range.(again if the software / device menu supports it) You can also try a shorter password, and see if that's what's hanging them up. Alot of these devices are running on somewhat buggy software / microcontrollers internally. – Tim_Stewart – 2019-08-11T18:21:57.193
1@Tim_Stewart: Thanks for the suggestions, however, the thermostats do not allow me to set static IP addresses for them. (I'm working with ASUS tech support to try to diagnose the issue.) – ScottFred – 2019-08-12T00:23:23.690
I'm having the same problem but my password is all lowercase with some symbols and a number. However on my router I am able to see DHCP logs – Captain Man – 2019-11-04T03:34:03.113
Sorry for double comment. Cannot edit on mobile app. I see this in the logs over and over and over.
Sun, 03 Nov 2019 10:20:56 received DISCOVER from 00:D0:2D:[snip] Sun, 03 Nov 2019 10:20:57 sending OFFER to 255.255.255.255 with 192.168.1.150
About once every five seconds. It has worked in the past but usually when it stops working it is very hard to get it going again. This is the deepest I have dug. I don't know much about DHCP but the logs seem to show something very very odd. – Captain Man – 2019-11-04T03:37:23.783