"Ethernet has a self-assigned IP address and will not be able to connect.." ?

I'm using a Linksys router and am wired over to it through a Netgear switch and things have worked for me no problem.

I don't buy the case that this is a serious flaw in OS X..something as basic as this would've been fixed a long time ago..

I'd imagine that it might be an issue with the router, cabling or something else..

Regards

It's worked fine for me with my iMac for weeks too - and many months before I got the iMac. A number of people have posted up about this problem and many simply don't seem to have found solutions..

alexjholland said:

cwa, my 15 metre ethernet has always worked fine with the many devices I've used it with; and my router has the latest firmware.

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Cardinal rule of troubleshooting network issues is to start at the physical layer and work your way up. Not all networking hardware is created equal, and although your iMac probably uses an off-the-shelf chipset, I have seen circumstances where certain NICs were more sensitive to cabling than others. Do yourself a huge favor - move the iMac close to your router and use a good quality cable and see if the issue persists. If it does not, you know what your issue is. If it does, we can continue further.

Simply put, if your car doesn't start, you need to check to see if there is fuel in the tank before you start rebuilding the engine.

This problem has popped up over the internet and one ex-Genius has referred to it as a serious critical flaw in OSX that he doesn't know how to resolve in many cases.

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Complete and utter rubbish. The foundation of OS X (and in particular, its networking stack) is BSD (a UNIX variant), which has been tried and proven in industrial-strength applications for 30+ years. As a professional network administrator, I can pretty much guarantee you this has nothing to do with OS X.

No disrespect meant to Apple "Geniuses", but my experience suggests that most of them, while well-meaning, have very little expertise in anything that's not Mac-specific. Networking may seem simple, but it is actually quite complex. Much like I wouldn't expect a plumber to troubleshoot an electrical issue, I wouldn't assume that a computer technician (particularly one versed solely in a single platform) to troubleshoot a network issue. They are not one in the same.

If you mean a number of people have posted about self-assigned IPs then I'm not surprised anyone ever posts a solution because in most cases the problem is usually a network configuration error and not an inherent issue with their computer or operating system. A self-assigned IP basically means you have a bad network setup. In some cases it might point to a hardware issue but that's rare.

I noticed from your screenshot that you were connected with a static address of 192.168.1.22. Your DNS is wrong unless your router is configured as a DNS server so if you tried to access a web site by name it will fail; otherwise; I'd say you are actually connected to the network. It's easy to test if you are familiar with the ping command. You can run ping from Windows or a Mac. Open a terminal and type "ping 192.168.1.22" ip address based on your screenshot. Your computer should respond. If not, your network setup is probably bad. If that doesn't work, I'd plug directly into the router, bypass the switch and test again.

And just so we know a baseline - could you click on the Airport (because this is working) in the network prefs, then do another screenshot of the data it gives there?

ukchucktown said:

If you mean a number of people have posted about self-assigned IPs then I'm not surprised anyone ever posts a solution because in most cases the problem is usually a network configuration error and not an inherent issue with their computer or operating system. A self-assigned IP basically means you have a bad network setup. In some cases it might point to a hardware issue but that's rare.

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So many things can go wrong that can cause a computer (any computer) to default to an APIPA address, that this is absolutely no surprise to see a plethora of posts and opinions as to the cause. It's much like Googling the terms "transmission problem Honda". Do transmissions problems happen in Hondas? Sure. But they happen in a lot of other vehicles too, and for a variety of different reasons. The same goes for any complex machine and a specific problem that can happen with such a machine. It doesn't make that machine is any less reliable, or more trouble-prone.

I noticed from your screenshot that you were connected with a static address of 192.168.1.22. Your DNS is wrong unless your router is configured as a DNS server so if you tried to access a web site by name it will fail; otherwise; I'd say you are actually connected to the network. It's easy to test if you are familiar with the ping command. You can run ping from Windows or a Mac. Open a terminal and type "ping 192.168.1.22" ip address based on your screenshot. Your computer should respond. If not, your network setup is probably bad. If that doesn't work, I'd plug directly into the router, bypass the switch and test again.

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I don't think DNS is coming into play yet. We're not that high up in the model. DNS simply converts human-friendly names to machine-friendly IP addresses. We've got the cart before the horse here, because we're not even trying to resolve DNS names yet - we don't even belong to a network properly at this point.

I'm not sure I agree his machine is not connected to his network. The screenshot he posted shows his computer connected with an IP address. If his router address is actually 192.168.1.1 and there are not other issues then 192.168.1.22 should work fine. All he needs to do for confirmation is test with ping from another computer on his network. If the ping test fails he should direct connect to his router and test again. I'm not trying to resolve his DNS issues. I'm pointing out his DNS is probably wrong so don't try testing with DNS names. To test Internet access try pinging 74.125.91.147. That's a Google server.

One more suggestion: disable your AirPort connection while you are testing. It's not a good test of your Ethernet connection if the Airport is active and working.

ukchucktown said:

I'm not sure I agree his machine is not connected to his network. The screenshot he posted shows his computer connected with an IP address. If his router address is actually 192.168.1.1 and there are not other issues then 192.168.1.22 should work fine. All he needs to do for confirmation is test with ping from another computer on his network. If the ping test fails he should direct connect to his router and test again. I'm not trying to resolve his DNS issues. I'm pointing out his DNS is probably wrong so don't try testing with DNS names. To test Internet access try pinging 74.125.91.147. That's a Google server.

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You're absolutely right. I guess I got hung up on the APIPA assignment. I'll shut up now, carry on

I agree with all CWA & ukchucktown have suggested. Please do try another cable and close to the switch if you can and if that does not work, right into the router.

You're absolutely right. I guess I got hung up on the APIPA assignment. I'll shut up now, carry on

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Nah, I got lucky when I noticed the screenshot he posted was connected. Hopefully the OP responds today because I'd hate for someone to return a quality computing product for something inferior. I just replaced a D-Link router with an Apple Extreme this weekend and our Windows Netbook gave us way more trouble than any of our Mac computers when it came to network reconfiguration. The Macs reconnected after a restart. Even though none of the settings changed I still had to delete the old network configuration on the Netbook and add it back again.

BTW, two thumbs up for the Apple Extreme. The performance blows away my D-Link 655. It was well worth the price tag.

ukchucktown, I agree and hope he comes back and does not return that machine. Something is wrong somewhere and between all of us, we are nailing it down if he will just try all that was suggested. I also agree with that default router address in therefor DNS is probably why he was not able to surf the web unless he put in IP's and not URL's. The green shows he was connected.

Thanks CWA for editing that large pic of his. I was going to and had a health issue and had to rest a few. Looks great the way you edited it.

Hey guys, it's 2222 in the UK and I'll be all over this tomorrow night. I just finished a string of night shifts and fell asleep this evening.

Thanks for all your help so far and I'll try all your advice and respond tomorrow night - thanks!

Any luck?

Hey guys, apologies for the delay - firstly, it's good news!

I've been super-busy at work this week so sat down yesterday to finally tackle unplugging my iMac from its many MIDI controllers etc and plug it into the hallway router, when I thought I should take one last look at my connections.

Low and behold, a nice green light and working IP on my ethernet connection. I deactivated my wireless to check and it's been working ever since (around 24 hours).

Whether this had anything to do with yet another restart I don't know, but I'm grateful - and will leave my settings alone! Photo of current setup below..

Glad to hear it's working. I just wonder what got it working? Thanks for the good news!

You haven't got internet sharing turned on have you?

No? I activated that on an old Windows PC once; but not on my iMac. Everything has its own cat6 1Gb ethernet connection!