Network keeps cutting in and out...

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Level 2

387 points

Network keeps cutting in and out...

I have a 2009 Macbook Pro, and over the last couple of days my network is getting really flakey. I am now running the NetworkDiagnostics program constantly so that the lights show. I will see that I lose network connectivity -- web pages won't (re)load, Facebook stops updating or shows pictures as broken links, sometimes my Skype, Adium and/or iChat goes offline. When I look over at the lights, they are green all down through ISP, and then Internet and Server are red. A couple of times I have caught it with Server green and Internet red. If I go through the reconnect sequence in the NetworkDiagnostics, it will come right back. Or maybe I'm fooling myself that anything I am doing matters, and it just comes back on by itself...

Wednesday night both my daughter (she on her iPad) and I were having problems getting and staying connected so we didn't try to use netflix. But last night we watched netflix and it stayed up like a champ all evening, while my Internet/Server lights kept going red.

At work, ISP is LISCO, I connect via an ethernet cable. No one else at work seems to be having any network problems.

At home (30 miles away in a different state topologically far from work), ISP is Frontier, and I connect via AirPort card to either my wireless router or another wireless router that is configured as an access point.

Last night at home I also tried tethering to my iPhone -- carrier is Verizon. It was doing the same thing.

On a lark, I removed 8.8.8.8 as the top entry in my DNS lookup and rebooted -- didn't seem to make any difference.

I don't really understand in any detail what the NetworkDiagnostics program means by having these lights for "Network Settings", "ISP", "Internet" and "Server" -- does anyone understand better what this is telling me about what is worng?

macbook pro, Mac OS X (10.6.5)

Posted on Sep 13, 2013 12:53 PM

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Answer 1

Best reply

rck77

Level 1

19 points

Jan 30, 2017 9:36 AM in response to cathy fasano

I don't think what's being reported is a problem with the ISP. Cathy's problem description has her computer having this problem in multiple places, multiple ISPs -- like going through the phone hotspot to a different ISP, instead of her household's network to the usual ISP.

I have this problem as well ... on iMac / Sierra / OS X 10.12.2 ... network keeps cutting out ... with symptoms as described by Cathy ... iMac's Network Diagnostics display generally shows red on ISP & Internet & Server ... but, my iPhone, on the same WiFi network, has full connectivity to the Internet. So it's something in the iMac -- or in the iMac--AirPort Extreme connection.

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Answer 2

cathy fasano Author

Level 2

387 points

Jan 30, 2017 9:41 AM in response to rck77

In my case the problem was that my airport card was in the process of dying. It's been dead for a couple of years, and I've been using one of those little ones that you plug into your usb port.

But there can also be problems with the networks that you are connected to. At my husband's office (a college wireless network) the wireless connection goes up-down-up-down at a steady pace, with about a 1-2 second period. So I can't actually establish a connection. I have given up trying to trouble shoot and just use a wire. (The internet connection here is blazingly fast, and the only way to take full advantage is a wire anyway.)

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Answer 3

rck77

Level 1

19 points

Jan 30, 2017 11:19 AM in response to cathy fasano

Thanks very much, Cathy.

That gives me an idea. Hearing that your AirPort card in your computer died made me reflect on my situation, and, a possible workaround. My problem is isolated to the iMac, as the other network devices in the house do not experience these outages. (The iMac will show on Network Diagnostics 'green' on WiFi, WiFi Settings and Network Settings, and 'red' on IPS, Internet, and Server, and have symptoms of no Internet connectivity. Meanwhile the other devices have good solid Internet connectivity.) It seems (cannot be sure) that the network connection on my iMac dies when it gets "busy", has a big load on it. I suppose that might be an indication of a dying AirPort card in my machine. I have a spare Airport Express device, so a workaround for me will be to plug the iMac into the Express, and see if the network connection holds up.

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Answer 4

Camelot

Level 9

54,333 points

Sep 19, 2013 8:47 PM in response to cathy fasano

To answer your question it will help with a little network background.

By and large, the internet is built as a series of clients (e.g. your MacBook Pro), servers (e.g. Netflix, Google, etc.) and network providers (e.g. your ISP) who link them all together.

Whenever you do anything on the internet, your client (MacBook Pro) sends a request to the server, which then sends back a reply. There may be many network providers in the middle of that connection that handle the routing of that request.

What network Diagnostics does is look at all the steps to try and determine where the failure is.

In Network Diagnostic's terms:

Network Settings - this is your client's configuration - is it setup correctly to talk to the internet

ISP - this is the network provider that you connect to (and pay)

Internet - this is the intermediate network providers between your ISP and...

Server - the actual server/company you're trying to interact with.

Now, from what you're saying, your ISP connection stays green and the problems tend to be 'upstream' from there... i.e. in the Internet and Server levels. Unfortunately these are almost completely outside of your control.

The best solution I can offer is to contact your ISP's support department and report your experience. It is *possible* that the problem is inside their network, where they connect to other ISPs (e.g. it could be their links are saturated and causing the drops), and if that's the case they should be able to do something about it. If the problem is upstream (in some other network) then the ISP may be able to work out a solution

If the problem is at the server itself then contacting the site operator might be in order, but I'm guessing this isn't just one site that's affected, which tends to point away from it being the server-side that's at fault.

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