Thunderbolt ethernet self-assign IP issue

[crazy$hark]

So today, seemingly at random, my internet stopped working (I have a modem which I use to connect to the internet via the Ethernet). When I looked in the system settings, it says that the computer is self assigning an IP address and isn't able to connect to the internet. This is a problem for me because ethernet is the only way I can connect at home. I went out and tried connecting to wifi, the internet worked fine. I tried multiple solutions proposed online (renewing DHCP, deleting the "com.apple.alf.plist." file, restarting modem, trying other cables, even trying to connect to the ethernet in other locations). Nothing works. Can someone help me with this please.

I am running Mavericks on a 2013 Retina MBP

 

[joecool99]

Power cycle the router. SMC+ PRAM rest.

 

[simonsi]

Check you haven't hit the routers max connected devices, some are set by default to only connect 16 devices on DHCP.

 

[crazy$hark]

Power cycle the router. SMC+ PRAM rest.

Check you haven't hit the routers max connected devices, some are set by default to only connect 16 devices on DHCP.

I probably didn't make it clear enough, but I don't have a router. I only have a modem and I connect via Ethernet. I've tried power cycling the modem, but no change.

 

[simonsi]

I probably didn't make it clear enough, but I don't have a router. I only have a modem and I connect via Ethernet. I've tried power cycling the modem, but no change.

You said you had "restarted the router"....

You also said you had tried connecting via ethernet in "other locations", what did that mean? Would it not get an ip address via ethernet on any network?

It may be your ethernet port, in which case you may be better swapping your modem for a combined wifi modem router or connecting a wifi access point to your modem and connecting via wifi.

 

[duervo]

You said you had "restarted the router"....

You also said you had tried connecting via ethernet in "other locations", what did that mean? Would it not get an ip address via ethernet on any network?

It may be your ethernet port, in which case you may be better swapping your modem for a combined wifi modem router or connecting a wifi access point to your modem and connecting via wifi.

If it is the Ethernet port, then it would be A LOT cheaper to just replace the thunderbolt-to-ethernet adapter than to buy a wifi access point or modem/router ... Unless the underlying cause is the thunderbolt port itself, and not the adapter.

At any rate ... Not enough data to accurately determine cause. Failing the addition of more info, I would just try a different Ethernet cable, then different TB-Etheret adapter, and see if the problem goes away after each test. If it doesn't, try different Ethernet port on "modem" (it may already be one with integrated router, which is what I'm inclined to believe since the Op states they can connect via wifi.) if none of that works, call ISP for further guidance, because at that point it's most likely something with the "modem" which should be handled by them at that point.

 

[Wymapper]

Initial Problems with Ethernet Adapter ON MBP 11,3

I just purchased a Gigabit Ethernet Adapter Gigabit Ethernet Adapter and had initial dropping of the connection to my network Time Capsule from a mid-2014 MPB11,3. After reinitiating Network Preference-Thunderbolt Ethernet a few times it has stayed connected. I usually keep WiFi turned off unless I'm mobile to increase security, I hope.

 

[Wymapper]

I replied to soon, still have the intermittent gigabit adaptor problem. Right now it's working. Applecare said it's the adaptor, I may exchange mine to see if it works. I, also, have the problem on Yosemite Beta 2 release, next time it fails, I'll do a manual configuration. And maybe slow it down, but why have thunderbolt except it's fits the thiner MBP case.

Any other suggestions out there?

 

[Wymapper]

Local Apple contract store tech had the nerve to tell me not to use the Apple thunderbolt Ethernet adapter just use wireless. He said he used the adapter in store and it worked. The problem I have is intermittent, sometimes it works for an hour. After spending almost $3,000 for a MBP and an adapter I need it to work. I use the MBP on the road, and I want the security of hard-wired web access, I don't do business over WiFi, and sometimes data volumes are too large to use the more secure phone/hotspot. I asked for a replacement adapter.

If the new adapter doesn't work I'll go third party, maybe a USB3 dock with gigabit Ethernet.

 

[Wymapper]

New Ethernet Adapter works.

Contacted AppleCare a second time and 2nd level Senior Tech ordered a new Gigabit Ethernet to Thunderbolt Adapter, sent second day. This one works flawlessly. I guess you need to be persistent. The Apple Vendor store didn't solve my simple problem and involved five trips. Still an Apple fan, a user for over 29 years, I'll order directly from Apple in the future.

 

[Heynonny]

I have looked around for years for a solution to the problem of intermittent ethernet-to-thunderbolt connection to a PB. Complicated by the fact there have been one and maybe two OS problems causing similar symptoms which were fixed. But the underlying experiences continue for many. Of course never at the Genius Bar!

The underlying problem is mechanical. The plug (mine and I'm sure many others) does not make continuous contact within the PB and once contact is momentarily broken it is hard for the OS to reestablish contact. This is why there are so many solutions posted all over the place. Rebooting, change from port 1 to port 2 (or vice versa), replacing configuration files, deleting the connection and setting up a new one, adding anther angel to the head of the pin. ANYTHING will seem to work, because nothing does. Do a rain dance and that might reestablish contact (especially if that jostles the PB a bit), but it would have anyway if you did nothing and waited long enough.

I finally took some strips of gaffer tape and fastened the damned plug down so tightly no amount of moving the PowerBook and stress on the cord can budge it. The PB has been running for five days without a single interruption! I have NEVER before made it more than two days. I know the tape will eventually stretch/loosen and the intermittent disconnects will start again; I'll just re-tape.

You have to really think out the angles and stress points to get a secure taping such that the plug can't move the least little bit despite normal movement on your lap or picking up/laying down the PB. The whole plug has to be PULLED TIGHTLY top & bottom towards the PB and your thin strips of tape have to be reinforced to prevent slippage/stretching. It's a really ugly solution, but it works for me.

EDITED TO ADD: Tape lasted for two weeks before loosening to the point I started getting disconnects again. Not too bad; will try to get it tighter this time.

 

[Heynonny]

I happened to run across this just now. I never got much more than 2 weeks with taping, a couple of times 3. Trying a few times along the way without tape it went back to hours.

So the tape works, but it's a real pain. I tend to run wireless unless I'm doing some intensive network traffic and then I tape down the adapter for that period of time and until the taping fails.

If I buy a new Mac laptop, anybody happen to know if this has been solved by now?