New problem with G5: Losing Internet connection

Posted by Pierre Igot in: Macintosh
February 21st, 2006 • 3:57 pm

In the past couple of weeks, I have started experiencing a rather weird and annoying problem on the G5 Quad. To understand exactly what’s going on, you need to have an idea of what my network setup is.

As regular Betalogue readers know, I am on dial-up. But I am not directly connected to the phone line from the computer via modem. I actually share this dial-up connection with my wife. To share the connection, I use an old AirPort Base Station (Graphite), which has its own internal 56K modem. The Base Station’s modem is connected to the phone line, and the Base Station is configured to use my dial-up login information to establish a connection with my Internet service provider.

Then the AirPort Base Station acts as a DHCP router and automatically distributes IP addresses in the 10.0.1.x range to our computers, i.e. my wife’s PowerBook G4 (Titanium), still running Mac OS X 10.3, and my G5 Quad running Mac OS X 10.4.5 (and also occasionally the G4 MDD, when I wake it from deep sleep).

The PowerBook G4 gets its connection to the Base Station via AirPort only, but the G5 Quad is actually connected to the Base Station both via AirPort and via Ethernet. I have an Ethernet hub connected to the Base Station’s Ethernet port, and on that hub I have the G5 Quad, and a couple of wired printers. Both printers are AppleTalk aware, so the G5 Quad and the PowerBook G4 use them via AppleTalk, not via TCP/IP (although that would be possible as well, with fixed 10.0.1.x addresses for the printers).

In other words, I have a local AppleTalk network with the AirPort Base Station and the Ethernet hub, and the Base Station provides the uplink to the Internet via dial-up for all computers on the network. (Sharing a dial-up connection between two or more machines is obviously not a very good idea, but that’s our only option at this point.)

The problem I am referring to in the title here started occurring a couple of weeks. The symptoms are very simple. All of a sudden, the G5 Quad completely loses the ability to connect to the Internet. I cannot browse the web. I cannot check my mail. I cannot access FTP servers. I cannot do anything. All Internet-aware applications behave as if I wasn’t connected to the Internet at all.

When this happens, if I go to the PowerBook G4 and try to browse the web, everything works fine. So it’s obviously not a problem with the Base Station.

I’ve tried a number of things to eliminate the problem. I’ve tried to restart the Base Station and reconnect to my ISP. I have tried renewing the DHCP leases on my G5 Quad. I have tried turning AirPort off on the G5 Quad and using the Ethernet connection exclusively. I have tried the exact opposite (switching the Ethernet port off and using AirPort only). I have tried switching between the two Ethernet ports available on the G5 Quad.

I have even tried restarting the G5 Quad altogether. Even after a restart, it’s still not able to get any kind of connection to the Internet. The local network still works fine. The G5 Quad still sees the local printers and is still able to print to them. But it cannot “see” the Internet at all.

And then all of a sudden it comes back. I have no idea why either.

Intriguingly, another thing has started happening lately, although I am not entirely sure it started happening around the same time, and I am not entirely sure it’s related. I strongly suspect that it is, however: sometimes I seem to lose the connection to the ISP (i.e. it looks as if the modem hangs up), and when I try to reconnect, Internet Connect dials in and starts communicating with the ISP’s servers, but then says that my user name or password is incorrect, which is obviously not true. I try again and again, and I keep getting the same error message. And then all of a sudden it starts working again.

The other day, I was on the phone with my ISP, but when I figured out that things were still working fine with the PowerBook G4, that pretty much eliminated the ISP as the source of the problem. I was actually on the phone while the problem was happening on the G5, and the ISP tech person couldn’t see anything wrong at his end. Obviously if things were working for the PowerBook, the problem was not with the connection to the ISP itself. The problem disappeared by itself after about half an hour.

Then today it happened again. This time I phoned Apple. I figured that I have AppleCare coverage for three years for the G5 Quad, and it quite clearly looked like a problem with the G5.

I immediately got in touch with a friendly tech support person. I had to explain the network setup in extensive detail, obviously. He suggested a couple of things that didn’t make any difference, and then he suggested power-cycling the AirPort Base Station and the Ethernet hub. I told him I had already tried power-cycling the Base Station when the problem had occurred earlier on, and it hadn’t solved the problem. But I had never tried power-cycling the hub.

I power-cycled both and, lo and behold, my Internet connection was back on the G5 Quad. So it looks like power-cycling the hub fixed the problem.

We decided that this fix would have to be verified the next time the problem occurs. So he agreed to leave the case open, and gave me a case number. Obviously having to power-cycle the hub is not a “solution.”

What I find strange is that this problem would start all of a sudden in the past couple of weeks. I have a sneaky suspicion that it could very well be a problem introduced by the latest system update (10.4.5), which causes some kind of “scramble” in the network that requires a power cycle (or a long wait) to get cleared. Part of my suspicion is due to the fact that I remember reading about other people losing their Internet connection in Mac OS X with no apparent reason—although usually these people report that restarting the machine fixes the problem. But then, my hardware setup is a bit peculiar, which might account for the peculiar symptoms.

Out of curiosity, I also went to the Console and looked at the system log. At 14:47 this afternoon, i.e. around the time the problem started again, I see the following section:

Feb 21 14:47:45 G5 kernel[0]: AppleBCM5701Ethernet: 0 4 setupCopperPhy - link is down
Feb 21 14:47:45 G5 configd[34]: AppleTalk shutdown
Feb 21 14:47:45 G5 /usr/sbin/AppleFileServer: AFPServer::AbnormalATListenerShutDown - clear listener
Feb 21 14:47:45 G5 configd[34]: AppleTalk shutdown failed, status = 71 (retrying)
Feb 21 14:47:46 G5 configd[34]: AppleTalk shutdown
Feb 21 14:47:46 G5 configd[34]: AppleTalk shutdown complete
Feb 21 14:47:49 G5 configd[34]: posting notification
Feb 21 14:47:49 G5 lookupd[3080]: lookupd (version 369.2) starting - Tue Feb 21 14:47:49 2006
Feb 21 14:48:20 G5 kernel[0]: AppleBCM5701Ethernet - en1 link active, 10-Mbit, half duplex
Feb 21 14:48:20 G5 configd[34]: AppleTalk startup
Feb 21 14:48:22 G5 launchd: Server 2513 in bootstrap 1103 uid 0: "/usr/sbin/lookupd"[3080]: exited abnormally: Hangup
Feb 21 14:48:22 G5 configd[34]: posting notification
Feb 21 14:48:22 G5 lookupd[3091]: lookupd (version 369.2) starting - Tue Feb 21 14:48:22 2006
Feb 21 14:48:25 G5 configd[34]: AppleTalk startup complete
Feb 21 14:49:38 G5 kernel[0]: AirPort: Link DOWN (Client disAssoc 0)
Feb 21 14:50:20 G5 configd[34]: AppleTalk shutdown
Feb 21 14:50:20 G5 /usr/sbin/AppleFileServer: AFPServer::AbnormalATListenerShutDown - clear listener
Feb 21 14:50:20 G5 configd[34]: AppleTalk shutdown failed, status = 71 (retrying)
Feb 21 14:50:20 G5 lookupd[3116]: lookupd (version 369.2) starting - Tue Feb 21 14:50:20 2006
Feb 21 14:50:20 G5 configd[34]: posting notification
Feb 21 14:50:20 G5 lookupd[3117]: lookupd (version 369.2) starting - Tue Feb 21 14:50:20 2006
Feb 21 14:50:21 G5 configd[34]: AppleTalk shutdown
Feb 21 14:50:21 G5 configd[34]: AppleTalk shutdown complete
Feb 21 14:50:39 G5 kernel[0]: AirPort: Link Active: "Maison" - 00022d300a1a - chan 7
Feb 21 14:50:41 G5 configd[34]: posting notification
Feb 21 14:50:41 G5 lookupd[3122]: lookupd (version 369.2) starting - Tue Feb 21 14:50:41 2006
Feb 21 14:52:24 G5 /System/Library/CoreServices/ Login Window Application Started
Feb 21 14:52:24 G5 /System/Library/CoreServices/ removeDisplayMapping: _CGSUnmapFramebuffer returns -536870206
Feb 21 14:52:24 G5 /System/Library/CoreServices/ removeDisplayMapping: _CGSUnmapFramebuffer

Obviously some of this stuff was caused by my fiddling around with the network settings after the problem started happening. (I didn’t note the exact time it started, unfortunately.) But the first line looks pretty suspicious to me. I wonder what this “setupCopperPhy” thing is. Is it something I did or is it the first symptom of the problem? I will have to double-check the next time the problem occurs, by looking at the console log right away, before attempting anything.

Obviously, I really could do without this problem. It’s bad enough to be stuck with a dial-up connection. But when even that doesn’t work reliably, one really does feel cut off from the world!

7 Responses to “New problem with G5: Losing Internet connection”

  1. Greg Balanko-Dickson says:

    I had the same problem and I replaced the Airport Base Station (Snow) and that fixed my problem. Seems the Airports have a habit of failing like this.

  2. Tr909 says:

    Hello Pierre, (should i have ever told you about console and system logs :-) ? )
    This can be nasty things, network troubleshootings. There were some strange hubs a few years ago that would act up in certain situations. I always suggest a branded one (Linksys, 3com, sweex Is your airport running on the latest firmware? In network sys.prefs. you could disable al ports, apply, quit sys-prefs, restart sys-prefs, enable network ports, enter a name/something for DHCPclientID, (set DNS to IP of your base-station or to DNS from your ISP) and then apply.

    Other hints (through
    – Reset PRAM (helped in a previous system-update garbling ethernet) (start the computer and press CMD-ALT-P-R until you hear the startup chime a second and a third time)
    – Apple support: You might try setting the ethernet port to a fixed speed (i guess you don’t have a gigabit ethernet hub) you could try 10Mbit/Half-duplex for debugging purposes (or 100Mbit/full) instead of auto-negociate:

    Good Luck….

  3. Tr909 says:

    oops, i did’t read that article of yours good enough…

    Why do you have two connection to the base station?
    copper-wired and airport… loose one and you probably
    should be fine. (radiation shy as i am i would like to
    suggest keeping the faster 100Mbit copper connection)

  4. Tr909 says:

    sorry (three comments is to much, i know) but power-cycling the hub looks like you force the G5 to fallback to the airport connection. Make sure you have unique DHCPclientID’s for airport and ethernet. What is your priority order for network ports? (network-prefs, show-port-configurations, which ones are checked and in what order are they: airport or ethernet first?) …uncheck ports you don’t use (internal modem, infrared, firewire, bluetooth) i prefer ethernet at top of the list becasue it’s the most fast in response and connection. My setup i have “show airport status in menu” on and in the airport menu i set “turn airport off”.
    You probably want to try this setup for some time.
    My (somewhat informed) guess would be that the double connection to the airport is the culprit. This generally is a strange setup.

  5. Pierre Igot says:

    Greg: It’s hard to imagine that this might be caused by the Base Station. After all, it’s still working fine with the PowerBook G4 at the same time, and even when I switch the G5 to use the AirPort connection only, it still won’t work on the G5.

    Tr909: I have two connections because otherwise I would be unable to monitor the status of the AirPort Base Station from the G5. The Ethernet connection to the AirPort Base Station gives you no control over the base station. You cannot see its status, and you cannot connect/disconnect the modem. I did find a third-party Java utility that does this over Ethernet, but it’s a bit crude, and my G5 came with a built-in AirPort card anyway… Also, even if I suppress one of the connections, the problem is still there. I am not too concerned about radio waves either :).

    As for power-cycling the hub, once the hub is back on, the G5 recovers the Ethernet connection to the AirPort Base Station and uses that as the primary one again.

    The Ethernet port is at the top of the list in my Network system prefs, i.e. it’s the priority connection. But even if I change the priority order, or disable/disconnect one of the ports/connections, it still doesn’t fix the problem (once it has started occurring). I have unchecked all other ports.

    I really don’t think the double connection is the culprit, as I have been using this setup for years without any significant problems. Certainly this problem is a new one. It could very well be, I suppose, that Mac OS X 10.4.5 introduced something new that doesn’t like the double connection as much as previous versions of OS X did.

    But we should still remember that these multiple connections are all active by default in Mac OS X. So the system is designed to be able to handle multiple connections at the same time.

    In any case, I am afraid the problem is probably quite complex. I’ll just have to wait until the next time it happens and try various things again.

    (My Ethernet hub is an old SureCom EtherPerfect 505ST. It has never given me any problems.)

  6. Tr909 says:

    apple system-updates have tightened abiding the system to the specs before (memory in 10.2.8-ish)…
    …The Ethernet connection to the AirPort Base Station gives you no control over the base station. You cannot see its status, and you cannot connect/disconnect the modem….
    This is something i can hardly believe, have you tried the “airport management tools” from (via: ) And did you change DHCPclientID’s (ethernet one and airport one) to be different from eachother?

    …it still doesn’t fix the problem (once it has started occurring)…
    imho better the problem should not start at all. fixing it during the issue is another totally different branch of sports.

  7. Pierre Igot says:

    I suppose in theory this might have something to do with Apple tightening the specs… although the fact that it works fine for several days and then all of a sudden goes wonky tends to disprove that.

    I am sorry if you can’t believe that Internet Connect cannot control the AirPort Base Station modem via an Ethernet connection, but it’s true. It might work with the newer AirPort Extreme base stations, but it definitely doesn’t work with the original ABS. If you don’t have AirPort and are connected to the BS via Ethernet, you get an IP address via DHCP, but that’s it. You cannot see the Connected/Disconnected status of the BS, and you cannot connect/disconnect the modem.

    The AirPort Management Utility that you refer to doesn’t seem to work with the old AirPort Base Station at all. It tells me that I need AirPort 3.4 or higher! (I have AirPort 4.something.)

    I didn’t try fiddling with the DHCP settings yet. I am waiting for the problem to occur again. One step at a time… If I change too many things now, and the problem doesn’t occur again, I’ll never know what the cause was.

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