Question Random devices losing internet and/or LAN access.

[IceBoy109]

About once a week I seem to be encountering a problem with my home network where some devices lose connection to the internet and/or LAN. At this point, I'm just trying to figure out if this is symptomatic of a hardware failure, or if it sounds like an issue with DHCP, or something else so I can know where to start with my troubleshooting.

The interesting thing is that the devices that lose connection don't necessarily have anything in common with one another and it's not the same ones every time (though, I think my phone does lose connection every time). Disconnected devices may occur on either the 2.4 or 5GHz band or may be wired. Some devices will lose internet and LAN connection whereas others can still access DLNA files but can't access the internet while other devices can still access both. When I lose internet access on my phone (via Wifi), switching bands doesn't help.

Some Devices and relevant details:
Netgear R7000 (Latest Firmware Version: V1.0.9.64_10.2.64)
Obi202 (not set as DHCP server)
Synology DS1513+
2.4GHz and 5GHz networks have different SSIDs
Approx 40 devices connected ranging from chromecasts, Ring Security Hardware, Phones, computers, printers, etc.


Troubleshooting Steps Taken:
Factory Reset (Full Disclosure: I didn't redo my port forwards or other settings manually. I backed up my settings and reloaded them after reset)

Thanks in advance for any input.

 

[kanewolf]

How many of those 40 devices are WIFI vs wired? Could your R7000 be overheating? There are a number of posts about that happening.

 

[Ralston18]

In addition, with 40 devices involved, there is a reasonable chance that a duplicate IP is being created.

Especially if one of those devices (knowingly or unknowingly) was reset/lost power/updated and returned to default settings.

Are you using any static IP addresses? If so, ensure that those static IP addresses remain reserved on the router by device MAC and that that the assigned static IP address remains outside of the allowable DHCP IP address range.

And remember to check the allowed number of devices on the router. All too easy to have the actual number of devices creep up to and exceed any set limit. Especially if guests are around.....

Check the router's logs if available and enabled. The logs may reveal some issues, problems, or conflicts.

Take a big picture look at your network.

Use a utilities such as nmap and netstat to scan your network. Zenmap provides a friendlier interface for nmap.

https://supportcommunity.milestonesys.com/s/article/using-Zenmap-and-netstat?language=en_US

Easy to find similar links about the utilities and how to use them.

 

[kanewolf]

With 40 devices on your network, (I have about the same number), I recommend a spreadsheet of all the network info. MAC addresses, static IP addresses, DHCP range, etc.

 

[IceBoy109]

Thanks for all the great tips.

kanewolf: I have 9 wired devices. At any given time, I will have approximately 30 devices connected which includes 2.4G, 5G, and wired devices. Not sure how to really gauge if it's overheating, but there hasn't been any excessive use of the network since before this started happening. I went ahead and created a spreadsheet and even in a worst case scenario I don't see myself hitting that cap of 32 devices per band (unless wired devices take up some of those numbers).

Ralston18: Whenever an authorized device connects to our network I set up an address reservation for it. In the Netgear interface it allows me to provide a custom device name so it allows me to better identify duplicate hardware from one another. But...hold on...

"...ensure that those static IP addresses remain reserved on the router by device MAC and that that the assigned static IP address remains outside of the allowable DHCP IP address range. "

wait wait wait -- I never knew that if I set up a static ip from a device itself that it had to be outside of the DHCP range! Who knows how long i may have had a device set up incorrectly. Rather than adjusting my DHCP range of addresses it'll probably be easier for me to log in to the various devices that I may have set up a static IP address for and disable them all as I have address reservations already in play.

I will check out those utilities you mentioned, but checking those static ip address settings will be my first step for sure. Thank you both!

 

[IceBoy109]

One down (synology diskstation)...

 

[kanewolf]

Trying to keep this kind of stuff straight is why I ended up with the spreadsheet. My DHCP range is 150 - 199. I use the 200+ for network related hardware, including my two Synology units.

 

[IceBoy109]

The Synology NAS was the only device that I had set to a static IP address, and while I'm hopeful to not have any of my random dropouts occur I'm not sure if this was the likely culprit. In doing a bit of research, the problem with having a static IP that falls within the DHCP range is that the server doesn't recognize or care about a device's internal static IP address settings. But, as I had mentioned in a previous post, I make sure to always set up an address reservation for any and all devices that connect to our network -- the Synology NAS included. So, unless I misunderstood something, it seems unlikely that the Synology having a static IP address assigned to it could have had any kind of IP address conflict.

All I can do is wait and see.

 

[IceBoy109]

Welp -- it happened again. When it happens, I can't seem to connect to the router via ethernet or wireless so I'm unable to access the log without first resetting the router. Unfortunately, when I power cycle the router, the log gets cleared. Kinda useless if this happens. But, I'm attaching a screen grab of the log anyway -- 192.168.1.13 is my Synology.

The odd thing is that I can still access my synology router from outside of my local network, and I can send WOL commands from a raspberry pi to other machines on the network, but I can't connect to any of the devices that are turned on via WOL. Something really screwy.

Just taking ideas again at this point. Thanks.