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

I got an iMac i7 about four weeks ago and looked forward to easy, great computing. It works fine, but has developed a serious networking error that may see it returned for a refund.

Specifically, my ethernet port says "Ethernet has a self-assigned IP address and will not be able to connect to the Internet."

I have tried deleting my locations and starting from scratch; deleting my ethernet connection then creating a new one; deleting some network preferences files in my system preferences; and of course renewing my DHCP lease.

This problem has appeared across forums, with no proven method to fix it. In fact, one alleged former Genius said it's existed since Panther and is a serious, critical problem for which their appears to be no cure for many who encounter it.

It's simple - if this isn't fixed I'm returning the iMac. The wireless works, but I have a fully gigabit ethernet connection for good reason - wireless is second-rate; particularly when I'm in a room with a lot of insulation from my wireless router.

Any ideas on how to fix this?

Thanks

Call Applecare and they will walk you through a solution. It sounds like you are using Windows knowledge to try and resolve a Mac issue. Call Applecare and let them guide you. It is possible that there is a problem with the machine and they can help you find it.

I'm using the only advice offered throughout my Googling. Others have called Applecare and achieved nothing - and if they had received a working solution, I'd be surprised no-one has provided it to the multitude of forumites who have suffered this.

So I will call them - in their incredibly office-unfriendly hours - this week and hope for the best. Right now I'd have faster internet with a Tescos netbook.

I'm probably doing something similar to what you are trying to accomplish, and I'm also new to the Mac coming from a Windows world. I do better one on one, so I made a reservation at the expert counter in my local store - they fixed a different problem I was having right then and there...

Back to your question, though. I wanted to set up my Mac like my Win machine - manual network addresses pointed at specific devices.
click Apple icon, upper left corner.
click System Preferences.
Internet & Wireless window - click Network icon.
Click "Ethernet" in list on the left.
select dropdown "Configure IPv4"
Enter the addresses you need to use. I did this...
IP = 192.168.0.33
Subnet = 255.255.255.0
Router = 192.168.0.1
DNS = 192.168.0.1
Search domains = blank

Time spent learning how to do things on a Mac = not much + well worth it. This Macbook runs Windows apps much better than Windows does, and the hardware is sooo much nicer.

Which router are you using right now? Does it have the latest firmware on there? If the DHCP has no issues over wireless, it should conceivably not have issues over a wired connection..

You can easily circumvent this issue by setting up a static IP address until a better resolution is found.

DHCP addresses are convenient and absolutely required for locations with lots of devices, but for a small home network, static IP address work just as well..

Regards

Wheelguy, I typed in those settings and got a green instead of an amber light on my ethernet connection - but no web pages load so I had to turn airport back on again.

Raz0redge, my iMac and consoles are all connected to a Netgear GS608 in my bedroom, which is in turn connected to a Linksys WAG320N.

I have logged into the Linksys and have the latest firmware, but have never logged into my Netgear router - and am not sure if I even can?

Could you explain how to do a static IP?

Cheers

That is a really strange issue as I have never had issues with any Mac and a wired connection. What are you using the two routers for and how is everything hooked up?

Opps, Scratch that. The Netgear GS608 is a Switch. What is the IP range of the Linksys router? That might explain why putting in the numbers you were given did not get you internet. Reason I ask is normally Linksys uses 192.168.1.1 as the router IP and if you put in 192.168.0.33 it would not work.

Well the WAG320N is in our hallway, simply acting as an ADSL router for our BT phone line; and a 15 metre stretch of cat5 cable runs out of the back down to my basement conversion bedroom, where it connects to the Netgear 8 port switch, which all my devices are attached to.

It's a great, fully gigabit setup that's worked pretty much flawlessly.

What IP Range is the Linksys router set for? Usually like I said above it's 192.168.1.1 with most Linksys products.

192.168.1.1 is what I type to get into the Linksys interface - is that what you meant?

Yes. On the iMac try a manual IP and put in say 192.168.1.55. See if you still can't connect to the internet.

Right buddy, just tried that IP using the settings put forward by wheelguy and no luck. I then tried converting the Router and DNS settings to 192.168.1 as well - still no luck.

I'll be keen to try anything else you suggest, but like I said - a lot of people seem to have encountered this problem and really hit a brick wall. I'll try to remain optimistic though!

did you set the router address in OSX to 192.168.1.1? You left out the last number.

Also I take it if you use DHCP you get nothing?

Can you do a few screen shots of your network settings in OSX? Especially all the tabs in Ethernet.

If you are new to OSX, hold Command+Shift+3 and it will take the whole screen. If you want just the network screen, Command+Shift+4 then point at the panel and hit Space then release the mouse. It puts them on the desktop.


Apples page is down for now but here is a URL to the cached version. People with your issue having fixes. Might help.

http://webcache.googleusercontent.c...lnk&gl=us&client=safari&source=www.google.com

Have a look at this link. Have to say use the same modem/router and it works beautifully.


Mac Wireless Problems? Guide to Troubleshooting Airport & Wireless Problems on your Mac

The screenshot is attached below dtravis and I'll check out your link now Harry - cheers guys

The static info looks good, except the DNS server. That is most certainly not your router..you need to use the DNS information from your ISP provider..

Without the right DNS IP address, you will not be able to resolve any names to IP addresses..

Regards

I have not encountered this issue on a Mac before, but I have seen it on PCs - most notably with homemade cabling.

When a computer (any computer) connects to an Ethernet network, there is a brief auto-negotiation process, wherein, the computer and switch decide which speed they can comfortably transfer data at. If there's a falling out during this process (due to cable integrity, noise or any other factor), sometimes the computer will just "failover" to an auto-assigned IP address.

Assuming this isn't the issue (and my apologies if you've already tried swapping the cable), then I'd suspect an issue with DHCP.

After this auto-negotiation, your computer will broadcast, seeking a DHCP server. If the DHCP server (your router) fails to respond in a timely manner, again the machine will failover to an auto-assigned IP address.

In this case, my first inclination would be to check for a firmware update for the router.

I'm not sure what my BT (England) DNS is, but I tried Open DNS at 208.67.222.222 and it still doesn't work..

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.

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.