C7 Not accessible on LAN when internet down

I have a C7 on my LAN, which I access using a Static IP from PC.
I also have Dashboards with Cloud links saved on my Phone.
This evening my ISP is down, and I can't access the hub from my PC.
The router is still allocating the Static IP, and I have rebooted the Hub and the router a number of times :frowning_face:

What is weird, is that I can access the Cloud Dashboard on my Phone (different ISP)

You cant access the cloud or any links to the cloud when your ISP is down. You’d want to use local links or the static ip.

That's the weird thing the Cloud dashboard was working, but I couldn't access the Local IP (I don't have local dashboard links saved, as I'd use the PC when at home to connect direct)

ISP is up now and I can connect to the Static IP again.

Something else weird, I could connect to one of my IP Camera streams from the LAN, but not the others.
The one I could connect to is linked to another WIFI AP as it is far from my router.
Maybe this "Three" Router Sercomm LTE2122GR has issues providing a LAN connection when there is no internet?

Networking is not my strong suit, I only have a "working knowledge".... :slight_smile:

It may have something to do with the DNS servers configured in your router...? If it is configured to use Google's by default? Just a guess....

I do feel like this may have come up before, so search of the Community would be worthwhile.

@mark.townshend I've seen this with some ISP provided routers. They won't route locally when the wan port is down. (I'm looking at you comcast) The solution is to plug everything into a switch then plug the switch into the hub. That way as long as devices still have an ip they will still talk to eachother via ip. (They won't name resolution though if you're using the router for DNS). Just another reason not to use ISP equipment.

Note: Being rather pedantic here but if you reserve an ip in your DHCP server that is a reservation vs setting the ip directly on the device itself, which is called static...:stuck_out_tongue: It does help when posting messages to make that distinction. :slight_smile:


What I have found is that even with cloud endpoints as shortcuts for my dashboards, they revert to local when on the same lan. (I have even noticed the message "switching to local...." when opening the dashboards occasionally. However, I would think you could also access your HE interface locally. Might be worth trying a DHCP reservation instead of a static IP. I have seen many posts throughout the forum that speak of weird behavior with static IP's that resolved with the use of DHCP reservations.


I did have a quick look at getting an AX router, and just use the Sercomm as a Modem.

The Sercomm list the Static IPs as "Static DHCP" so yes they are reserved rather than physically set on the Hub itself

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Good point about the Cloud Dashboards redirecting, but I had WIFI off on the phone so it would use 4G data on another network the phone wasn't even on the LAN.

Need to do some more investigating I think.
Shame the Router is a faff to get at in the loft.

NB-be very discerning when replacing your router. There are some models that are let's say "half cloud" where some of the function depend on the internet being up. One example is the router used on Optimum online in the NE USA. It's a real POS and you can't configure but a few options. Another example is the Wyze mesh router. My suggestion, and it's free to try, is to get an older laptop or mini PC and load PFSense on it. It has enterprise level features and is extremely powerful. However you'll need an access point or 2 to deliver the wifi. You could even use an older router in bridge mode to deliver the wifi signal. Check out PFsense videos on youtube

My head is exploding. I hope my current Spectrum/Charter supplied setup runs forever.

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