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Sorry in advance for the long post. I've been working this issue for the past 4 months and I am at my wits end. I work for a small business that moved into a new office in December. When we moved in, it was a new build in the suite, so we had a company come in and set up our cabling, VOIP system, and network.

4 months ago our internet started going out. It would drop and we would have to power cycle the wireless router. But power cycling would only works sometimes, and we could go all day having to power cycle it every 30 minutes. So I had our network guy come in and change the router. We replaced the router with one of the same model, and it started having the same issue a few days later. So I called our network guy again and we tried a different model. This router would randomly change its IP address and that would take our internet and phones offline. We replaced this router with another that did the same thing. Finally we have our current router but it continues to drop internet signal and will sometimes give employees a message that they cannot join this network. Power cycling will normally correct the issue, but we have to do this multiple times a day.

My network guy and I were baffled on what would cause 5 different routers to fail. We decided we would need to look into other factors that could be impacting our network. During this process, I had the modem replaced and the internet service provider out to examine the setup and they could not determine an issue on their side of things.

I did discover the back-up battery pack for the cabinet was putting out low voltage (109 volts comparted to the regular 120). I replaced the back-up battery pack and the issue went away but only for a week.

I’ve also had an electrician out to examine our wiring and to ground the cabinet and make sure everything else was wired correctly.

But despite all of this, my internet keeps dropping constantly.

No one else in the building is having any issues. The problem is contained to our office.

I am completely out of ideas of what could be causing this issue. I don’t even know what questions to ask to try to continue troubleshooting. Has any heard of anything like this or does anyone has an idea of where to look for the cause?

jmclaughlin6569
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  • Have you tried unplugging the router from the outgoing ISP cable thus creating an isolated NAT? Any stability issues within the local network? Also, try opening up wireshark and seeing whats going on in the network - maybe you will discover an overlap of activity and the problem occuring. – Enigma Jul 11 '14 at 20:05
  • My network guy did that and he wasn't able to find a problem. – jmclaughlin6569 Jul 11 '14 at 20:06
  • If you chain two routers at the entry point, do they both fail or just the outermost one? – Enigma Jul 11 '14 at 20:07
  • We had a wireless router and then and extender that was set up in the conference room. When the first router started failing, it was replaced with the one that was the extender from the conference room. That one ended up failing as well. Does that answer your question Enigma? – jmclaughlin6569 Jul 11 '14 at 20:10
  • Mostly. It sounds like it is a problem of where your network is connecting to. Is it connecting directly to the ISP or is it connecting through a gateway either somewhere in the building? – Enigma Jul 11 '14 at 20:15
  • Do you have any wired machines on the router/network? – MrWhite Jul 11 '14 at 20:22
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    w3d: Yes there are wired machines on the network and they go down as well. Enigma: I've downloaded Wireshark and am capturing packets. But this is all new to me and I have no clue what to look for. Is there a specific error I should be looking for in these? – jmclaughlin6569 Jul 11 '14 at 20:40
  • I would be suspicious of some sort of RFI or PLI, perhaps a malfunctioning motor nearby, or even a LED lightbulb or a fluorescent on a dimmer. – Daniel R Hicks Jul 11 '14 at 20:44
  • And, of course, there's always the possibility that someone is sabotaging you, either someone from the outside (via the net somehow) or a disgruntled employee. – Daniel R Hicks Jul 11 '14 at 20:45
  • RFI is radio frequency interference, correct? I'm not sure what a PLI is. Do you know how I would even check for these? – jmclaughlin6569 Jul 11 '14 at 20:47
  • I can't say that someone isn't doing this from the outside somehow. But I'm not sure why anyone would want to. We're a small business and I know everyone who currently and has ever worked here. I can't imagine any of them being able to cause this. – jmclaughlin6569 Jul 11 '14 at 20:50
  • PLI - Power Line Interference. – Daniel R Hicks Jul 11 '14 at 22:16
  • Think back as to whether any sort of maintenance activity was performed in the area around the time that this problem started -- replace an HVAC fan, change out a fluorescent fixture, install LED lighting. Even a new refrigerator in the break room could be the culprit. – Daniel R Hicks Jul 13 '14 at 02:13
  • (And don't forget that a single bad cable in your rack could be at fault.) – Daniel R Hicks Jul 13 '14 at 02:43

2 Answers2

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I would first recommend isolating which side of the access is truly dropping (or both). Clients (and by clients I mean your servers, desktops/laptops, etc.) should be able to connect to your internal network and the router, even if you are unable to access the internet. If this is the case then you have at least isolated the issue is between the router and external access. If your clients are dropping from the network as a whole, then it does not matter if the router is still capable of accessing the internet, as your clients will never be able to access the internet if they cannot connect to the router.

I have had luck troubleshooting these types of items by eliminating as many factors as possible to get to the root cause.

You mentioned that you power cycled your wireless router, so are all these connection drops occurring strictly to wireless devices? If so, during an outage, does a device that is hardwired through the router continue to work properly?

The find with the inadequate power was a good one, have you also gone through the logs to see if the router is restarting, or other such activity that could explain the symptoms? Also, have you updated the router BIOS to take advantage of any specific fixes that have been released since the router shipped?

Last thought has to do with the IP changing... How are you managing IP's on the network? Check to make sure you do not have IP conflicts that are causing your router to drop off. For example, I have seen where someone had a server manually configured to an IP that was in the range of IP's that DHCP was handing out... which meant that when a guest laptop connected to the network and was given that IP lease, conflicts ensued. Make sure the same is not happening with your router.

If you can provide more information on your network setup and type of router, I am sure others may have other suggestions of items to check.

PacketTrace
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I am not a network specialist, but I would throw out two things to look at. You seem to be using POE devices. I've seen something similar happen at a hospital and it was due to the two areas not sharing a common ground. The ground was described as "floating" and zero voltage at one side of the campus was higher than the other. Power as a result flowed from the higher side to the lower side causing problems. You may want to check your grounding at all stations.

The other issue would be that you have a bad POE device somewhere in the chain. How you would isolate this - not sure. You could in theory put in another switch between the router and other devices and see if the switch takes a hit.

Blackbeagle
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  • I had an electrician in yesterday and he checked all the grounds. There is not a network extender anymore, I took it down while troubleshooting. So everything is confined to one rack that is grounded. – jmclaughlin6569 Jul 11 '14 at 20:44