I have a bizarre issue that just started after almost a year of continuous operation. I’m throwing this out there to see if anyone else is experiencing a similar issue or might be able to help point me in the right direction.
Two days ago, I noticed my SmartThings Hub was offline and started displaying a blue flashing LED. A call to ST support informed me that this indicates a failure to procure an IP address. I went through the usual troubleshooting procedures, rebooting the hub, the switch, the firewall, etc… no joy.
I checked my layer 3 switch and it doesn’t have any active DHCP registrations for the ST Hub mac-address.
To ensure DHCP is still working, I placed my Fluke LAN tester on the same switch port and it was readily assigned an address and was pinging out just fine. Also, everything else on this switch is receiving addresses from DHCP and communicating without issue. The only device suddenly affected is the ST Hub.
I moved the ST hub to a ethernet port directly off my Cisco ASA firewall and it lit up green and went online immediately. Now I could call this a job well done and retire to a well overdue icy cold beer and try to enjoy a Friday night… Yet the problem is that everything I want my ST Hub to talk to is on the “inside+wireless” network that is served by the Cisco switch and it’s DHCP server:
Without these devices communicating, SmartThings has not much to do here.
Due to the way my house is wired, It would be extremely laborious to re-cable these devices to the guest VLAN to accommodate whatever has changed on the ST Hub. I’m left scratching my head wondering, why was this setup compatible 2 days ago but not today?
For the record, I have not made any changes to my switch, firewall or ST Hub configurations in quite some time. Wish I had as it would be easier to correlate to cause.
Rough layout was:
ST Hub – Cisco SG300 L3 Switch (serving DHCP and multiple VLANs) – Cisco ASA5506-X Firewall – Cable Modem
As of today, the ST Hub only works if plugged directly into the Firewall. Other devices are able to negotiate DHCP address assignment from the switch without issue. There are no filters applied to the ports or VLANs, no custom MTU sizes, no port-security… in fact nothing out of the ordinary. There are indeed adequate addresses available in the DHCP pool. And to be sure, I’ve even tried static DHCP assignment to the ST Hub mac address. Yet DHCP on this Cisco Small business switch will no longer chooch with my ST Hub.
Next step is to re-install a packet analyzer and try to see what is flying over the wire…
If anyone has run into this issue or has a suggestion, I’d greatly appreciate it. Lest I start snaking cables through my walls all weekend trying to work around whatever has suddenly changed.
Thank you in advance,