Losing Internet connection: Trying to narrow it down

Posted by Pierre Igot in: Macintosh
March 1st, 2006 • 5:18 pm

Like most computer troubleshooters probably know, network problems are a royal pain in the neck. There are numerous possible hardware/software combinations and there seems to have an infinite number of possible ways for things to go wrong. Hardware failures are mysterious and occur without warning and without explanation. Software failures can be due to system updates, server problems on the ISP side, etc.

In addition, some problems can be extremely difficult to track down because they only occur intermittently. And I am currently faced with precisely one such problem. I have already written a couple of posts on the problem, and I have already spent a fair bit of time trying to troubleshoot the problem, but I am afraid I am not making much progress.

Here’s a recap of the latest steps I have taken.

  • I have eliminated the Ethernet connection between my G5 and my Ethernet hub altogether. So now both the G5 and the PowerBook are connected to the network exclusively via AirPort. The Ethernet hub is still connected to the AirPort Base Station, but is only used for the two Ethernet printers that I have. This new arrangement has not, however, eliminated the problem, which occurred again earlier today.
  • I have tried to replace the Ethernet hub with another one that I had, but unfortunately, that other one doesn’t seem to work as well. With that other hub, I am unable to use both Ethernet printers. I can only use one (the HP LaserJet 5MP with an AsantéTalk LocalTalk/Ethernet adapter) or the other (the HP cp1700 with Ethernet card) over AppleTalk, but not both at the same time. If I connect the LaserJet 5MP with the AsantéTalk, then the cp1700 cannot be seen by the computers. If I connect the cp1700 only, it appears on the network, but then if I connect the LaserJet 5MP with the AsantéTalk to the network, it fails to appear, even if I power-cycle the AsantéTalk. Given that the two computers are no longer using Ethernet, however, I seriously doubt that the hub is the culprit. But I will try to live without the cp1700 for a few days, with the other hub, if necessary.
  • Yesterday I saw a post in a MacInTouch reader report from someone who had recently started experiencing similar-sounding problems. In his case, the connection appeared to be lost after 24 hours (with a DSL connection, by the sound of it). This led me to do some more research on the Apple Discussion forums, which yielded a number of threads reporting problems with the AirPort Update 2005-001 recently released by Apple. So I started suspecting that update, which I had installed on my machine (fairly recently, I think). The only way to roll back this update was to do an Archive & Install of Mac OS X 10.4, which I did. I reinstalled the system from the original G5 Quad discs (version 10.4.2), and then updated to 10.4.5, but didn’t install the AirPort Update 2005-001. (This particular update is a bit weird. It does appear in Software Update when I run it, but it’s not checked. The description says “This update fixes reliability and resolves AirPort compatibility issues with certain third party 802.11 cards and access points for Mac OS X v10.4.3 and later.,” but we all know that Apple’s descriptions rarely tell the whole story, so who knows exactly what this update fixes and why it is visible but unchecked on my machine. In any case, I didn’t reinstall it, suspecting that it might be the culprit. Unfortunately, this did not eliminate the problem, which occurred again today, after all this.
  • When the problem occurred today, it was just after I had been cut off by my ISP, which tends to happen every 48 hours, even though I have unlimited dial-up access. (I have a dedicated phone line, so I stay connected all the time.) I reconnected the Base Station’s modem to the ISP, and it appeared to work fine, but for some reason Safari was not able to see the Internet connection, and neither was Mail. Strangely, however, Speed Download, which was still running in the background and downloading files at a low 1 kB/s, seemed to still be able to continue downloading, and MenuMeters was indeed still indicating some network traffic, corresponding to Speed Download’s on-going downloads. So the Internet connection was not lost in every program on the G5—only in most of them! Very strange… I then went to the PowerBook and things appeared to be working fine. I could still browse with Safari and check mail with Mail. But then I just tried reapplying the network settings in System Preferences, out of curiosity. And after that the Internet connection was no longer working on the PowerBook either—even though Internet Connect could still see that the Base Station was connected via modem to the Internet. This thing is getting stranger and stranger!
  • I have a second AirPort Base Station (Graphite), which I used to have in another area of the house with an Ethernet connection to the first Base Station so as to create a roaming network. I have been unable to get this to work since upgrading my computers to Mac OS X 10.3 (i.e. for the past two or three years), so the second base station has been sitting on a shelf doing nothing. I tried to switch the base stations to see if the culprit might not be the one that I am currently using. That’s when I discovered, after much huffing and puffing, that this other base station actually appears to be defective! I am completely unable to see it from either computer via AirPort. It’s not completely dead, because I can actually connect to it with the AirPort Admin Utility if I connect it to an Ethernet hub via Ethernet and then connect one of my computers to the same Ethernet hub via Ethernet. In that case, the base station appears in the AirPort Admin Utility and I can configure it. But even after I configure it, the computer still cannot see via AirPort. And as soon as I disconnect it from the Ethernet hub, it completely disappears. In addition, I seem to be unable to reset the base station. Even if I press the button for 5 seconds as per Apple’s instructions, the base station still retains its existing settings. In other words, it looks to me as if this second base station is completely dead. It’s not dead in the typical way (with the red LED coming on and staying on permanently), since I can still access it via Ethernet, but it looks like the AirPort side of things is completely dead in the base station. This might also explain, in part, why I haven’t been able to get roaming networks to work in the past couple of years :).

What all this tells me, in a nutshell, is that things are still very unclear. The problem no longer affects just the G5. The PowerBook is also clearly affected, although only after network settings have been reapplied, i.e. when it has had to re-establish its connection to the AirPort Base Station. The AirPort Update 2005-001 is clearly not the culprit. But it still could be the 10.4.5 update on the G5. (The PowerBook is still running Mac OS X 10.3.) The problem started occurring around the time I installed that update, and it could still be that something between the AirPort Base Station and the G5 causes the base station itself to start acting up. What is for sure is that, when the problem occurs, the only way to get rid of it is to either wait for a rather long time (I haven’t been able to determine exactly how long) for things to “clear up” by themselves (presumably because something that causes the whole network to seize up eventually times out) or to power-cycle both the AirPort Base Station and the Ethernet hub. At least so far I have been able to clear the problem with one of the two, and I hope I won’t ever have a situation where these solutions no longer work. (As a reminder, restarting the computers themselves doesn’t clear the problem.)

This whole thing is a royal pain. I am still hoping that, in the relatively near future, we might be able to get some kind of local wireless high-speed connection to the Internet, which might help eliminate the problem—although I might have to eventually replace the AirPort Base Station itself by something else, either a new AirPort Extreme base station or a third-party product. With all the problems I have had with AirPort hardware and software over the years, I am tempted to choose a third-party product with a proper antenna and a better range than Apple’s hardware. On the other hand, as long as I am stuck with dial-up, I have to get a router with a built-in modem. I don’t know if there are many third-party products with such a thing. At least one of Apple’s AirPort Extreme base station models still has a built-in modem.

3 Responses to “Losing Internet connection: Trying to narrow it down”

  1. Paul Ingraham says:

    This is a long shot, Pierre. I haven’t read your posts on this carefully, so I may be way off here, and/or you may have already tried the solution. However, you never know — and if it’s no use to you, perhaps it will be to someone else. So, here is the result of my own long, exasperated AirPort troubleshooting process, which completely resolved nasty erratic connectivity problems with a single click…

    There is a somewhat sneaky but powerful preference in the AirPort Admin Utility:

    AirPort tab > Wireless Options button > Enable interference robustness

    Like I say, it’s a long shot, but it’s easy to suggest!

  2. soosy says:

    The only other thing I can think of that it looks like you haven’t tried is to turn off Appletalk on all computers. Appletalk isn’t always supported fully/correctly by hubs which makes me suspicious of it. It also seems to be treated somewhat as a legacy technology in OS X. You’ll have to print via IP but perhaps it’s worth a shot.

    You can turn off Appletalk in System Prefs->Network as well as /Utilities/Directory Access.app. Not completely sure of the difference… I think the first makes your machine appear on Appletalk while the second lets your machine see other Appletalk devices.

    Good luck!

  3. Pierre Igot says:

    Paul: I’ve never used “Enable interference robustness,” first because I have very little cause to suspect interference in my house, and secondly because I am afraid it will limit the AirPort range even further. But I will give it a try if nothing else works. (I don’t see why this option would fix a new problem that has just appeared in the past few weeks, but who knows…)

    Soosy: The problem is that we cannot print via TCP/IP to the LaserJet 5MP, which is our primary printer. So I simply cannot turn AppleTalk off. I am not about to buy a new laser printer just because of a network problem. :) It has worked for years and there is no reason why it shouldn’t continue working just fine.

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