Configure Hub 2245 For Static IP Address

[stewdog]

There are several posts regarding the use of Static IP Addressing on Insteon Hub 2245-222 but they are all old enough that starting a new thread seems to be the right thing to do, so here we go...

It seems that a lot of you are using DHCP reservation to achieve a specific desired IP address, which is a great strategy and one that I also make great use of. I like knowing the IP addresses of all of my devices and setting up DHCP reservations in the router (or whatever device on the network is serving DHCP, but most typically it is the router) is a great way to accomplish this. However, it is not without caveats. For example, if a power outage results in the entire network going down do to power loss, then when everything eventually does come back up, it is possible for one or more devices to be back online well before the router is back online and its DHCP request could time out and this could result in a useless default "private" IP address and therefore a useless device!

This is precisely what happened to my 2245-222 Hub at a vacation home an hour-and-a-half away. Naturally, I was prepared for the worst, thinking I was going to find a complete dead Hub (wouldn't be the first time). Plus, I was aware that an extended power outage had taken place several days prior. But I knew that I got lucky the moment I saw the green LED on the Hub. Sure enough, a power-cycle and the hub was back online and fully functional in less than a minute. So my educated guess is that it failed to obtain the proper IP address from the DCHP server (router) when power was restored because the Hub sent out its DHCP request well before the router was ready for it, but now that the router is fully functional, a reboot of the Hub restored its proper IP settings. BTW, the router is an enterprise-class Cisco router that takes well over five minutes to fully boot up.

I would like to change my 2245-222 Hub to a true Static IP address so that I never have this problem again. With a true Static IP set in the Hub itself, it will always come online with the specified IP address no matter what's going on with the router.

Many posts on this forum related to this issue only talk about setting up a DHCP reservation in the router to achieve a static IP. However, I think a true Static IP can be achieved based on what I'm seeing in the Insteon Android app, but I am looking for some confirmation that I'm interpreting the app correctly.

I went into the app (any screen), tapped Settings > Edit Settings > House. Scrolled down to the IP settings where it displays the Local IP, Public IP, Gateway IP, Subnet Mask and Port. Right below Port is DHCP with an ON/OFF switch, which was in the ON position. I changed it to off. I heard several beeps and clicks from the Hub. I even rebooted (power-cycled) the Hub and it is still completely functional and the app still shows the original network setting values. See attached screen shot of Insteon app settings.

My guess (and this is what I am looking for somebody to confirm for me) is that by simply turning off DHCP in the app (which means in the Hub), it more or less "locks in" the EXISTING network setting values so that these values will not change, thereby establishing a TRUE Static IP Address.

I simply cannot find any documentation to confirm my interpretation of what I am seeing based on the behavior of the app. Can anybody on this forum confirm that turning OFF the DHCP setting does in fact lock in the existing IP settings, thereby establishing a true Static IP?

Thank You!

[stewdog]

Follow up: I just called Insteon Support to see if they could answer the question for me. Besides my inability to make sense out of what the technician was saying due to her thick accent and the fact that my question was clearly way above her knowledge, it was a complete waste of time. The answer basically was that "The DHCP switch should be in the ON position in the app". Yeah, well it is now in the OFF position and it's working fine. I just need to know if turning DHCP OFF results in a Static IP address.

[SeanM]

More or less yes. The Hub will think that the IP address that was initially handed out by the router is assigned to it and will not budge, even in the event of a power outage or change or router subnet. It was needed for the old 2242-222 Hub that required port forwarding. The 2245-222 model does not need port forwarding so there is no real benefit to it unless you are using the Hub for serial communication and/or our sending outside network commands. Even then I would recommend getting a DDNS address and let the router do its job.

HOWEVER...Since you are using an enterprise router all bets are off on what the best practice for you would be. I would go get a cheap Linksys and throw it in between the Hub and the Cisco. That way while you are waiting for the Cisco to go through its POST process the Linksys can hand out IP addresses from its own pool. Then, when the cisco finally comes up and grants network access, the Hub will establish its channel and connect.

[stewdog]

Thank You SeanM! But I must ask, if having turned off DHCP in the Insteon app "More or less yes" creates a static IP address, why go any further? The static IP by itself will prevent this scenario from playing out yet again in the event of another extended power outage. Am I missing something?

[SeanM]

That is the more or less part.

The router is ultimately in charge of the assignment of IP addresses. Disabling DHCP in the app only "freezes" the IP address the Hub originally got from the router into the Hubs memory. After an extended power cycle, or outage, your router goes through is startup process and then looks for connected devices. There are a lot of variables here but the router may or may not remember the IP address it originally gave to any one MAC ID so there is the potential that it will give the Hub a different IP address creating an IP conflict...which will basically mean your Hub is unreachable until you perform a network reset. By configuring a reservation in the router you avoid that issue since the router knows what IP address to assign to the connected MAC ID.