Original SmartThings Hub - DHCP Problems


I have an original (KickStarter) Smart Things hub. It sat in the box for a LONG time, and I finally decided to get it going. I’ve been trying to get it working for the last several weeks – I had never installed it until I got the Amazon Echo and wanted to get the integration going.

When I first installed it, it came up and worked immediately, and then did it’s updates. Then after about a week or two strange stuff started to occur. I’ve found a REALLY strange issue related to DHCP and your hub that I cannot resolve. I’m hoping that someone can shed some light.

For some background, I’m a computer engineer, I write networking protocols, and I have over three decades of experience with DHCP … I’ve run a wireless ISP, and my house is thoroughly wired. I have three DSL lines at my house. I use DHCP for numerous devices across my network, and have about 60 devices that use DHCP in my house. I have a DHCP pool of 100+ addresses and they are not all used.

When I plug the Smart Things hub into my network … it just won’t accept the DHCP address being given to it. It asks over and over – sending requests about ever second or two. I can use a network analyzer and watch the packets go back and forth … the Smart Things hub sends the request – my Linux server sends the address – and the Smart Things hub ignores this and asks again.

I can plug any other device in the exact same port … and the other device will work fine. I can use the same cable, and the other device works just fine. I’ve moved the Smart Things hub all over my house, and even plugged into the main DLS modem … and it fails. I’ve tried multiple different cables also. I’ve used cables from other devices that work.

I can take a Raspberry Pi, or a laptop … use an Ethernet cable … plug into a port … and it works perfectly. Unplug the cable from the device and plug it into the Smart Things hub … no go!! Non-stop requests streaming in the DHCP log file.

NOW … I’ve twice left the Smart Things hub on my network – thrashing away for hours – and all of the sudden it will accept the address. Most of the time it appears to happen after almost an hour of non-stop requests.

What is happening? How can I get this resolved?

Defective network adapter? Bad cable? Are you running any multicast filtering or custom MTU sizes or jumbo frame support? Since you are advanced, these things on consumer network gear can cause issues.

Have you tried isolating it from your environment, simple consumer router and see if it works there?

Thanks for the reply, but if you read my post carefully you would see that I’ve done all of the standard - and extensive - debugging.

I have 50+ devices in my house that DHCP just fine. I’ve carried the SM Hub around the house connecting to all of the various ethernet cables and connections - that are working perfectly for other devices - with NO luck at all with the SM Hub.

IF I leave the hub - sending DHCP requests like crazy - for an hour or so, it eventually gets on the net … only to then drop off again later on or the next day. It repeats this cycle non-stop.

It was working earlier today, and now has returned to sending non-stop DHCP requests - and getting the responses and ignoring them. I’ve moved it three more times today.

SM Support is saying that they actually KNOW about this issue, and that I’m supposed to go and buy more hardware to fix their problem. I’ve asked them to work with me to fix their firmware or DHCP protocol implementation … not sure if they will.

I’ve also asked if this is only an issue with the original hub, or also with the new hub?

Bottom line … I’ve got countless IP devices working on my network with DHCP just fine. It’s just the SM Hub that is showing this issue. :frowning: