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December 24, 2012 6:22 AM   Subscribe

How can we pinpoint whether our network trouble originates with our ISP or with our router?

We have a small home network running from a two year old Time Capsule with two external disks attached via powered hub. All our devices are Apple. Lately we've been dropping shares a lot and d/l speeds are about twenty percent lower. We also find that devices are "forgetting" their default networks and reverting to secondary ones, always on our same LAN except when it's a 5GHz device, when it grabs the neighbor's net. It's as if 5GHz is the last to re-load.

We had everything optimized and running at maximum speeds for many months. We'll give our ISP a call but we're hoping this might look familiar to someone as they may start out saying the trouble must be with our older router.
posted by R2WeTwo to Technology (24 answers total) 2 users marked this as a favorite
So, for example, you become unable to access one of the disks shared by the hub from a device within the home network, something you ought to be able to do even if the internet were completely disconnected? That part at least is pretty unlikely to have anything to do with the ISP unless your setup is very different from the sort I'm familiar with, if you're in the U.S.
posted by XMLicious at 6:32 AM on December 24, 2012 [1 favorite]

I agree with XMLicious, accessing network shares should would without any issue whatsoever when the internet is completely down. Your ISP has nothing to do with issues of that nature.
posted by Brian Puccio at 6:36 AM on December 24, 2012

Router problem for sure.
posted by empath at 6:37 AM on December 24, 2012

We can access them once we re-mount the drives. I guess I was thinking of something that could so slow or otherwise impede our speed that the shares would just fall off, though I see what you mean.
posted by R2WeTwo at 6:52 AM on December 24, 2012

Brian, how do you get wifi when your internet is down?
posted by R2WeTwo at 6:54 AM on December 24, 2012

Wifi is just how your devices connect to your router, lack or presence of an Internet connection doesn't change that.
posted by kavasa at 6:59 AM on December 24, 2012

Think of WiFi as a cordless phone. The phone and base still work if the phone line is down, but you won't be able to make calls outside the house.
posted by Nonsteroidal Anti-Inflammatory Drug at 7:05 AM on December 24, 2012

Your router's job is

A. to connect your computers on your home network to one another, either with cables or with wifi, and
B. to connect to your ISP and therefore allow things on your home network to access the internet.

These two jobs are independent, and the router should be able to do job A quite happily, whether or not job B is feasible right now.

The best analogy I can think of: I can't get up my stairs past the big pile of books on the third step. Could this be because Amazon are having delivery problems? Also how will I get my books in and out of my bookcases if Amazon stop delivering over Christmas?
posted by emilyw at 7:07 AM on December 24, 2012 [1 favorite]

Internet---ISP Connection----[Cable/DSL Modem]----[Router]-----Local network

This problem likely exists in your local network. It would seem to having nothing to do with traffic passing to/from the internet, via your modem. Rather, this is a problem with the devices on your local network talking to each other, through the router or directly.

Do you have any network switches installed, or is everything on your local network cabled directly into the router ports, or on WiFi?

Is the machine hosting the shares in question cabled or on wifi? Is it just the airport? If possible try cabled connections for anything having trouble, to eliminate signal issues.
posted by snuffleupagus at 7:15 AM on December 24, 2012

Time machine, not airport.
posted by snuffleupagus at 7:20 AM on December 24, 2012

NS, but isn't it true that you couldn't even make local calls because the cordless phone wouldn't have any power?
posted by R2WeTwo at 9:00 AM on December 24, 2012

I get this and I know it's true because so many people agree, it's just that I don't think I'm making my question clear. I'm on meds. that cause this symptom and I worked really hard on my question to try and overcome it.

I thought our Time Capsule depended upon our modem to take our ISP signal and make it airborne. It's not a hotspot in a strict sense, so how can it work, make an Internet signal airborne, if the modem is not feeding it that signal?

Snuffleupagus, we have no switches and the hosting machine is wifi, but Time Capsule, when new and working well, is pretty independent, can run smoothly even with the hosting laptop a thousand miles away, or turned off.

I hope this makes sense. I love the analogies you're all coming up with. They're very helpful.

Would any of our logs tell us anything easily discernible?
posted by R2WeTwo at 9:09 AM on December 24, 2012

A cordless phone would have power unless the electricity was off too, you just wouldn't have a dial tone. But for example you'd be able to listen to old messages on the answering machine, if your phone was one that let you do that from the handset.

Even if your connection to the internet is down, if everything is set up and working properly with your hubs/routers/other networking gear your computers should be able to "see" each other and interact over the local network and access disks and printers and things shared by other devices and computers.

(Exceptions to every rule of course, that probably wouldn't be true if you're using Google Cloud Print or one of the other wacky newfangled services that routes things through a server somewhere on the other side of the world when you send things to your printer across the room.)
posted by XMLicious at 9:14 AM on December 24, 2012

Wow, this explains the times we were surprised to be able to IM when the network was down. This answers our question very well, thanks everyone. Look like we'll be getting a post-Christmas router for one another!
posted by R2WeTwo at 9:50 AM on December 24, 2012

I thought our Time Capsule depended upon our modem to take our ISP signal and make it airborne. It's not a hotspot in a strict sense, so how can it work, make an Internet signal airborne, if the modem is not feeding it that signal?

Alright, think of it this way -- imagine you're watching a football game on your fox news affilliate, and they lose their satellite uplink to the game from the network. The local station doesn't die when that happens, you just can't watch the game any more -- they'll put up some local programming, until they get the uplink going again.
posted by empath at 10:15 AM on December 24, 2012

The Internet is a network of networks. Your home network is still a network whether or not it is currently connected to the larger Internet.

It sounds to me like your problems can be completely explained by a problem with your home network.

One thing about your desscription stands out for me: why do you have secondary networks, and what are they? And why are your devices configured to connect to your neighbor's network at all?

The first thing I'd look at is whether you might have new sources of interference from neighboring networks. Do you have the time capsule configured to automatically chose its network channel? Is the firmware up to date?
posted by Good Brain at 11:49 AM on December 24, 2012

I know a bit beyond the basics, Good Brain, thank you. Our near neighbors and we have agreed to share bandwidth for short periods when a network is down for whatever reason. The intention is to give the afflicted party the materials needed to get up and running again. While troubleshooting we deleted their profile from all our devices but one and that one told us of the sequence, grabbing its network because our own was not working yet after the drop. All firmware and software is up-to-date and interference is a very real possibility as other near neighbors seem to have turned their network range up to counter neighbors on their other side. We have our range turned down but we've troubleshooted with it up, with no difference. Can anything be done for such interference beyond talking to these neighbors? We (along with others) have already had to speak with them about other things and would like to avoid piling this onto the heap.
posted by R2WeTwo at 12:17 PM on December 24, 2012

Great analogy, empath! DH worked for a local TV station and should have thought of this one.
posted by R2WeTwo at 12:19 PM on December 24, 2012

I never took the time to make devices static on the network. Could this be why it hasn't seemed as independent as it should be? We lose wireless printing every time the power goes out.
posted by R2WeTwo at 12:24 PM on December 24, 2012

Just to be clear, although it seems like you may understand all this already, you do not need your ISP connection working to make your signal "airborne." There is such a thing as a wireless ISP connection, but that's different than WiFi. (You may have seen it referred to as WiMAX, it's usually for metro areas).

Think of your network as coming in two segments: the "Wide Area Network" (aka WAN) which means the Internet in your case. Typically your ISP connection is via a DSL modem or cable modem. A DSL modem uses frequencies above the vocal ranges to carry data over the legacy phone system (or at least, that's the basic idea). A cable modem does something similar, except over the cable infrastructure. The main difference is that DSL connections are private circuits, and cable connections use a higher capacity shared loop. The WAN connection comes into your house and ends at your DSL or cable modem.

There's a short network cable that goes from your modem's network port into the "uplink" port of your router. That's the physical connection between your home network and the endpoint of the Internet connection, which you can think of as being in your modem. (This is fudging a little, as while your modem will have a public IP address, your router may or may not have one too depending on how your ISP does things.)

Sometimes customers will have a single ISP provided device that integrates the modem, router and wifi access point into a single box, which could cause some confusion. However, there are still logically discrete segments of your network. Just imagine two smaller boxes inside the device. The problems you are describing are characteristic of issues on the local side of the network, or LAN.

Again, in the simple home network case (like yours) the computers and devices on your LAN are those that are cabled to your router and/or connected to your router's wifi. (The router is also usually your only wireless access point unless you have extra access points set up.) WiFi is just an alternative to using a cabled port on the router. I still connects you to the local network segment, not directly to your ISP. If you're not using static addressing, its your router that assigns addresses to your wifi devices, just as with physically connected devices.

Thus, if you lose connection to the WAN because of a problem outside of your house, or because your modem fails, as long as your router and access point are up and running (and, again, even if its all in one box) your local cabled and wireless devices will be able to talk to each other. They just won't be able to see or be seen by the outside world.

Is it impossible for you to connect the time capsule and at least one client machine physically to your LAN even temporarily? Cutting out the wifi and making sure everything is working as intended on a simple wired network would be where I'd start.

As to static vs. dynamic addressing, giving everything a static IP can help clarify things for troubleshooting--but it's also not reallu the Apple way (which is to rely on Bonjour).

It's difficult to know what kind of DHCP conflicts or interference you might be having without being there....
posted by snuffleupagus at 4:04 PM on December 24, 2012 [1 favorite]

(Although there's no harm in trying a different wifi channel number in your router/AP's configuration. There may be too many people on the midband defaults, especially if you're in a dense area and someone has their TX power cranked way up. Conventional wisdom is to assume neighbors are on channel six, and to try 1 or 11 to avoid overlap. And it would make sense for different bands to come up in sequence after a reboot--the device is running through a sequential startup script or init sequence. )
posted by snuffleupagus at 4:20 PM on December 24, 2012

Thanks so much, Snuffleupagus. This helps a lot. I didn't go into detail because, frankly, it sounds pretty odd. I can tell you know your stuff, though, and who knows which detail might be revelatory. Feel free to pass on this if it's more than you want to take on. We're fine with a simple, wired, net, and, as you probably know, we're nearing the end of the typical TC life-span. The biggest problem is that DH's guest network is seen intermittently by the flowerpot iMac we created it for. (He needs to run OS 9 for something and it's not compatible with WPA). Tonight we confirmed that a neighbor is hopping on, which is new, but we know it's unlikely she could be bouncing him off. We're about to create a new guest and see how it goes. The flowerpot sits right next to a newer iMac but, strangely, whenever this occurs, we also have trouble getting an ethernet connection from the iMac to work. It did the first time and we used that for many months. Then it stopped working so we tried the wifi and it worked so we switched. It's not the Airport card because it picks up the other neighbor's linksys.

Other symptoms: When I launch Airport Utility the router has that triangle with the exclamation point in most of the time, where it never did before. It comes and goes and I must work quickly to make any troubleshooting changes 'lest it knock me off and make me start over when it comes back. As I said, shares (partitions on external disks connected to Capsule) fall off my desktop, presumably because the connection is dropping. This occurs more when I've stepped away than while I'm on. Browsing speed is down a little, iOs devices sometimes lose their connection and the only fix is to physically recycle the modem and router (seriously, we've tried restarting the devices, resetting network settings, everything) and, finally, IM has become buggy while it was very stable before. Curiously, we noticed today that this is happening when we're both on either the 5GHz or the 2GHz at the same time, which we should always be. I'll send and get an error that there are no destinations avail but he gets the message anyway. Then I can't see his reply...that sort of thing. He hasn't wanted to update the newer iMac next to the flowerpot so Messages has been out. We've been limping along with DropCopy.

This feels like way too much information. And on Christmas. Happy Holidays anyone reading!
posted by R2WeTwo at 6:14 PM on December 24, 2012

I forgot, SN, we use WiFi Analyzer to see who is on which channels and work with that.
posted by R2WeTwo at 6:19 PM on December 24, 2012

If anyone with a similar problem is reading this we had good luck with the "Restore to Defaults" option within the Airport Utility, essentially a hard reset. You can also press the reset button on the back of the device but I'm not sure for how long, as a quick press didn't do it. Our router is dying, but the reset took care of the most annoying of our symptoms, buying us more time.
posted by R2WeTwo at 12:54 PM on December 27, 2012

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