You should be able to take it to any Authorized Apple Repair Center.

Okay, looks like it happened around 10:30 pm or so tonight, so was able to get the answers for you guys for when it's in a Internet-less state.

I wouldn't be surprised, by the way, to find that it crapped out at about 10:38 pm or shortly thereafter. My system log advises me that I turned on the computer at 6:38 pm ... so add four hours to that ...

Anyway.

No, it definitely is not cached data. Here's what I got when it was down:


Yes. In the 'down' state, I am still seeing IP Address, Subnet Mask, and Router as white boxes with greyed-out filled-in numbers. The DNS servers are two empty boxes, but to their right, there are grey numbers. My domain name has something automatically filled in, my DHCP Client ID is an empty box, and the WAN Ethernet Speed is set to "Automatic (Default)."

(Am I right in saying that there would be some grevious security problem if I posted those numbers flat-out in a public forum?)

It appears to fail immediately:

2 more things I'd like to add to your already long list..
1) Do you have a firewall running on the iBook that might be blocking the DHCP request replies?
2) Just to confirm it's not the Mac, have we tried hooking the iBook directly to the cable modem?
Sorry if you already answered/did these, I didn't see them in earlier posts, but I read so many and have a terrible memory.

No firewall, and I did try a direct connection with success. Good ideas both.

dnstracer
 

From all that you have reported so far, it seem that the basestation has lost its connection to your ISP. It seems like this might be a problem with the DHCP lease that it gets from your ISP.

There are, however, a few strange data points.
1) I would have expected to see your basestation there in the first line of responses from your 'traceroute'. It seems odd not to have it respond when it apparently responds to 'ping'. You do get responses back from pinging the basestation ? (You didn't show what you got, so I have to ask.)

2) It is very odd that you apparently have DNS service from your ISP on your iBook even when the basestation connection seems "down".

I'm guessing that your iBook is caching the DNS info from earlier. By the way, I don't think that the 'arp' command will show you any possible DNS caches held by the OS. I believe that 'arp' is concerned only with your local network. This is corroborated by the fact that after doing a successful ping to my basestation and to www.google.com, 'arp -a' only shows this machine and my basestation.

To check on the DNS, the easiest way I know of is to use the command-line utility 'dnstracer'. You can download it via fink. Here's an example of using it:
The "206.47.244.79" you see at the beginning of that output is one of the two DNS servers that I get via my DHCP connection to my ISP.
You can see what DNS servers are currently used by your iBook by looking at the file /var/run/resolv.conf
(e.g. 'more /var/run/resolv.conf')
Check the date on that file too - it should correspond to the time when your iBook got that info from your basestation.

Re: dnstracer
 

Hmm... traceroute on OS X (or BSD in general -- I don't know) uses UDP instead of ICMP -- might make a difference. Unlike the version on linux there's no option to select UDP or ICMP. Try running it again next time with '-v' to get verbose output.

You're absolutely right about arp. It just gives you a mapping of IP addresses to hardware addresses. For all non-local IPs the hardware address is that of the appropriate gateway.

(Thanks for the pointer to DNSTracer. I'll have to take a look at it.)

Breen

Re: dnstracer
 

Before I go any farther, I should mention to everybody that I spoke with Apple this morning. Because it sounds like the problem is with the base station (since plugging the cable into the iBook yields no problem whatsoever, and the fix comes solely through resetting the base station), they're replacing it, since it's under warranty.

Both they and my ISP were pretty impressed with the level of troubleshooting you guys were able to help me with. THANK YOU!

They're sending a new one out, and I'm sending the old one back. I had heard that a batch of the AEBSs that were released around the time I bought this had gone bad, so perhaps this might just be bad hardware.

True enough, although I think it's the AEBS, and not the iBook, experiencing the problem.

Yes, I did, both in 'Net-less and okay positions.

I'm not so sure. I hardly ever visit some of the sites it was able to give me DNS info for. I'll try coming up with some really exotic URL, if I can, next time it's down.

However, I did download dnstracer. However, right now, even while I have active Internet, it doesn't appear to work. Perhaps it doesn't work through AirPort? Here's what I get:

Can anyone else with AirPort confirm that it doesn't work through it, or tell me of a differing experience? (Do you have AirPort, Hayne?)

As for:

I get:

It's dated Aug 23 10:01.

Those don't match up with the DNS servers which AirPort shows me in the Admin Utility.

Re: Re: dnstracer
 

Yes, I have Airport and the example dnstracer I showed above was via Airport. It shouldn't make a difference Airport or not. But my basestation is connected to a router which connects to my ISP, and so my basetstation is configured in "bridge" mode - so it just hands things over to my router, it doesn't do any DHCP or DNS.

The fact that 'dnstracer' fails to get anything from your basestation (which is your iBook's DN server) seems to mean that the basestation's DNS capability is not working.
As I mentioned above, this means that your iBook has been configured (automatically) to send DNS queries to your basestation. The "domain" entry is not DNS related - it sets the domain name for your machine.

You might try changing the Network Preferences on your iBook to have the DNS servers that you were given by your ISP.

Re: Re: Re: dnstracer
 

I don't understand what you're saying. When I'm in the "'Net-less" problematic mode, the DNS capability seems to be the only thing working, i.e., ping tells me the IP address of google.com, even if it doesn't connect. So how can this problem mean that the DNS is not working?

You seem to have a slightly atypical setup, with the base station bridging to your router connected to your cable modem. Are you sure that my setup should have identical capabilities/reactions to yours?

Re: Re: Re: Re: dnstracer
 

As discussed above, I don't really believe that your DNS is working when you are in the 'Net-less' state. I think you are just using cached information.
I think that if dnstracer shows a problem, there likely is one.
No - your setup is much more complicated as far as the basestation goes and hence is much more dependent on the basestation being properly configured and much more dependent on the basestation software working properly.

Have you tried what I suggested - entering the DNS servers in the (optional) box in Network Preferences?

[edit] Something else I should have asked much earlier:
Are you sure you have the cable modem connected to the correct port on the basestation? It is supposed to go into the WAN port. (see basestation docs)[/edit]

Re: Re: Re: Re: Re: dnstracer
 

Please note, Hayne, that any challenges I make to your assumptions aren't meant as discouragement or ingratitude ... but simply as part of the problem-solving process, and also my way of clarifying and learning where you're coming from. Hope you take it that way! :-)

The only reason I find that hard to believe is because I can get an IP address for almost any website in this "down" state. Tell you what: give me the name of a very obscure website you know of that you'd think it'd be unlikely I visited. I'll try pinging that when/if it next goes down, and I'll see if I get IP information. Would that be a good test, do you think? It could hardly cache an IP address for some place I've never been, right?

See, the thing that I'm not that certain about -- and please do excuse my doubt -- is whether this problem arises from a "problem" or our differing setups.

If anyone else is monitoring this thread, and has a simple cable-modem-to-AirPort connection, could you try installing the 'dnstracer' application and see what your results are?

If you don't mind the question, how is my setup more complicated? You actually seem to have the extra step of the router between your AirPort base station and cable modem, whereas mine is just a direct connection.

Not yet ... I'm trying to take things one at a time. ;-) My question relating to that, actually, was going to be: which of the various "DNS Servers" boxes?

Should I put it in the DNS servers box for the "AirPort" configuration? For "built-in Ethernet"? The DNS server entries in AirPort Admin Utility?

My ISP never actually gave me DNS server entries to put in, and I've never had to before. However, I note that AirPort Admin Utility is reporting 207.229.143.1 and 207.229.143.2 in greyed-out text to the right of the DNS server boxes.

Interestingly enough, when I use those as a value in dnstracer, it works ...

Is that particularly significant, do you think?

For a short time, yes, I was being stupid enough to have plugged it into the LAN and not WAN slot. However, that error was rectified and the problem persisted despite numerous reboots, etc. of the affected equipment after that.

BTW, a quick addition to this note:

New hardware is now on its way from Apple (as per earlier post), so it will be interesting (although quite disheartening) to see if the problem is reproduced with the new AEBS.

I am particularly suspicious of it being a hardware problem because I (again, only occasionally) cannot get in to configure the base station. I highlight the station and hit the configure button. A long pause ensues, and I'm then asked for a password -- which I shouldn't be, since the password's in my Keychain. I then type it in, and a slight pause continues. I'm then told that the Admin Utility can't configure the selected base station, and that an error occurred while attempting to configure it.

That problem actually pre-existed this one, and it makes me suspicious of whehter there are hardware problems involved in this routing/IP address problem ... and why I'm going to be keeping my fingers crossed that this new AEBS is a problem-solver ...

Re: Re: Re: Re: Re: Re: dnstracer
 

Of course. No problem. Best to not take anything that people say as gospel - verify it for yourself with test on your equipment and by googling the topic.
Okay - try www.hayne.net (very obscure)
I had said that your setup is more complicated as far as the basestation goes. You are relying on the basestation to do much more than I am.
Since your iBook is connected only via Airport, the "builtin Ethernet" section is not relevant. Put it in the Airport section on your iBook.
Your basestation seems (from the text to the right of the DNS server boses in Airport Admin) to already be getting the correct DNS servers from your ISP. So no need I think to put them in there - I think that would be redundant. But it is certainly something to try if it still doesn't work otherwise.
Was that when you were 'Net-less' or not?
That error is what you get if your Airport Admin password is incorrect. I do not have my A.A. password in my keychain (for security reasons since my Airport network is a more valuable target than merely this one machine - I have several machines on my LAN). Try removing the password from Keychain just to see if this fixes the problem of sometimes not being able to get to A.A.

And just to double-check on another thing - you said earlier that you din't have the firewall active on your iBook. But have you ever had any firewall software runnig on your iBook? (The firewall might be active even though Apple's preference pane doesn't know about it if it was done via 3rd-party software.)

Re: Re: Re: Re: Re: Re: Re: dnstracer
 

Thanks for understanding. I can't remember which famous Greek philosopher is the proper adjective ... maybe Socrates ... but there's a method of learning based on questions being asked and answered. I want to say it's the Socratic method. Anyway, I'm of the firm mind that the only dumb question is the unasked one, and when it comes to my Mac and related equipment, I'm especially inquisitive and wanting to make certain I understand as much as I can.

Okay -- I'll try pinging that next time I'm down, and I'll see if I can get a reaction. I've never been there, so I shouldn't have it cached. [Although based on the URL, I think I know who owns it. ;-)]

Oh, I see. Your router, in other words, takes some of the burden off of what your AirPort base station has to do.

That makes sense. Okay, the two values I got from the AirPort Admin Utility are now also in that slot in Network Preferences. We'll see if it prevents things from going "down" again.

That particular readout was when things were up. I will try it again when/if things go down.

I understand -- but the password I'm typing on these occasions is most definitely correct. Which is why I find the error odd.

(For reference's sake, by the way, the exact wording is: "The AirPort Admin Utility was unable to read the configuration of the selected base station. An error occurred while reading the configuration."

*shrug* Worth a try, and done. I do note that unplugging and replugging the base station also seems to solve the problem ... again, a reason why I suspect hardware origin for that problem.

A very long time ago, I may have downloaded Brickhouse ... but I don't even remember turning anything on, and hell, that might've even been on my iMac, not my iBook, it mentally feels so long ago.

In short, I'd say the likelihood of this particular one is very small, but if there's any diagnostic you want me to check to make sure that a firewall isn't currently active, let me know.

As a side note, by the way, it turns out that the second sentence of that error message is different when your password is incorrect ...

What I had been getting: "The AirPort Admin Utility was unable to read the configuration of the selected base station. An error occurred while reading the configuration."

Bad password message: "The AirPort Admin Utility was unable to read the configuration of the selected base station. The password you entered is not correct."

Re: Re: Re: Re: Re: Re: Re: Re: dnstracer
 

If you used Brickhouse then you can easily find out if it's running. Hit the Terminal and type:
If there's anything other than:
Then you're internal firewall (ipfw) is actively blocking ports. There are other firewalls out there that don't use ipfw (which is built into the OS X install). So if you used (later versions, v2 and up I think) Firewalk X or NetBarrier X, then ipfw won't show it.

Re: Re: Re: Re: Re: Re: Re: Re: Re: dnstracer
 

I'm good. And I definitely never used Firewalk or NetBarrier. So I'm firewall-free.

Well those were just two examples that I can think of, there may be more. But at least you're not using ipfw. The mystery continues... Where's Scooby when you need him?

Let me be more generic, then ... fairly certain I've never tinkered with any firewall software, period ...

My only hope is that as we rule out more and more things here, it becomes more and more likely that it's the one thing we ourselves can't test, a hardware issue, which would then be resolved with the new hardware arriving soon.

(God bless Apple Customer Service ... so far, nothing but compliments for 'em!)

It didn't.

And, indeed, nothing was found:

So the preceding successful IP addresses must have been cached.

As for running dnstracer when things are down:

Interestingly enough, with the DNS code typed into that panel, it automatically uses that address and not 10.0.1.1 for dnstracer, I suppose? But no result whatsoever; it just times out.

So, hayne, forgive me: what does this mean (i.e., what does all this data come together as)? Is this new data able to lead you to a successful diagnosis of what you think is wrong?

I don't really have a diagnosis.
It is somewhat comforting to have the DNS no longer mysteriously working.

It seems as though the packets being sent out by the iBook are not being forwarded by the basestation at all. I don't know why that would be.

One idea for something to try:
Connect the iBook with an Ethernet cable to the basestation's LAN port and turn off the Airport card on the iBook by using the Airport menu. See if it works that way.