Self assigned IP address

As for me, I've solved my problem by checking again the network wire to see whether it is broken or discontinued by electricity power or what. In this case, I think the problem is not in your computer, but in the network.

This is a post for dummies, like myself, so apologize my non-tech language 😉

I had the self-assigned IP problem for a week and tried all possible easy fixes:

-Reboot modem and devices (twice, sounds like voodoo to me)

-Opened system preferences/network/advanced/TCP/IP clicked renew DHCP license -->this would allow sometime one device to connect, but not all devices at once

-Opened system preferences/network/advanced/TCP/IP and under configure IPv6 clicked link-local only (same results as above)

-Even ruled out "interferences" setting up a 5.2 Ghz network (sorry if I'm using the wrong words, like I said, I'm quite ignorant about this)

Nothing worked.

My set up was a modem, three powerline extenders that connected via ethernet to 1) an airport express, 2) an i-mac, 3) an apple TV (if you have no idea what a powerline is read side note below on powerlines)

I finally understood what the problem was: I could only connect one device at the time, meaning that if I restarted the modem with only one device connected that device would work. If I had two or more connected the remaining devices had a self-assigned IPs.

Now for you dummies-like-me out there (I apologize to all techies out there for using wrong words, concepts etc... the modem receives internet from provider and gives it to your home. Internet works in numbers (IP addresses) that tell your modem what devices are connected to it. Now, modems tpically, can connect to one thing at the time. To connect multiple devices you need a router. The router looks exactly like a modem to me (ha ha) it's another little black box, but it will have multiple ethernet ports on its back. Airport express can work as routers (theoretically, as it turned out mine wasn't). The router generates a range of IP addresses, for example, if you are using your airport express as a router you can see the range under system preferences/network/advanced/TCP/IP it could be 10.10.00.01 to 10.10.00.200 (probably not, maybe this is an impossible range, like I said, dummy here, but it will look something like this to other dummies out there). Now, if that is your range and your devices have an IP address of 169.225.xxx.xxx you have a problem. Your device has an IP address not in the range determined by your router= you have no internet. To find the IP address of your device: on a mac system preferences/network/advanced/TCP/IP (I think it's the IPv4 address... maybe 😉 and it should have the first bunch of numbers identical to your router or within the range determined by your airport express) on my apple TV it was under settings/general/connection

The problem: I finally determined that the problem was that my airport express, for some reason, could only assign one IP address at the time. If all 3 devices were connected, only one would get a valid IP address. Basically, it was not doing its router job. Apple support were sweet as pie but useless and told me it was a problem due to my provider (which wasn't).

The fix: I plugged my modem into an old router I had lying around in the house from my pre-airport express days, restarted the modem and everything went back to normal 😍 I almost cried for joy.

My current set up:

1-cable from provider into modem

2-ethernet cable from modem into router (into the internet port, not one of the numbered ethernet ports)

3-ethernet cable from one of the numbered ports of the router into ethernet port of powerline extender, plugged into a wall

4a-2nd powerline extender plugged into a wall on a different floor. Ethernet cable out of that into my airport express to generate wi-fi

4b-3rd powerline into a different wall plug. Ethernet from that to i-mac

4c-4th powerline into different plug connected through ethernet to my apple TV

I hope this helps! 🙂

Side note on powerline extenders: I live in a big old house with thick walls and wi-fi won't reach everywhere. Powerline extenders are magic portals that allow your internet to travel through walls (ha ha). I have TP-LINK (TP-link TL-PA511 KIT AV500 Powerline Gigabit Adapter Starter Kit, up to 500Mbps). They're $60 a pair on amazon. The way they work: plug an ethernet cable from your router into the powerline, plugged into the wall (they have to be plugged into the wall to work!). Plug another powerline anywhere into your house (within a ridiculous distance, maybe 300 meters/yards or so) and internet will come out of that precious little thing at the same speed it came out of your modem=magic.

Side note on airport express: I think my airport express is glitchy but that said, I used airport utility to set it up. How? On a mac just look for airport utility (apple key+ space to open the search tab). From there click on wi-fi. If the utility does not see your airport express reset it with a pen, clicking that little spot that can only be pushed with a pen till the yellow light pulses fast a few times. For me, sometimes, it takes a couple of clickings to get there. Then wait. On the utility after a while if you click on "other wi-fi devices" on the up-left corner you'll see a number in the scrolldown menu: that's your reset airport express. Select it. Set it to create a wi-fi network (if that's what you need) name the network, assign a password and you should be all set.

For me after 4 hours, after reading all issues, implementing all solutions offered by community members, this combination worked for me. Follow these steps in order

1) Turn wifi off,Firewall off

2) delete every saved network profile in Network- advanced

3)Delete the below files in Macintosh HD-"Library"- "Preferences"-"SystemConfiguration"

.com.apple.airport.preferences.plist

. com.apple.network.identification.plist

. NeworkInterfaces.plist

Empy trash too.

4)Turn wifi on. In network configuration, click on assist me , then follow the wizard. Even after doing that, wizard will say "unable to save settings" but in a few seconds, mac will connect to internet

No Logic, nothing.... it jus worked for me ......

All the best

This is the trick that worked for me, thanks!

Though I wonder if it is a Mac or a Router problem: I have a new router (FRITZBox 6360) from a new service provider, the WIFI connection worked for some days, then the "self assigned IP" problem started. Since I still have the old router (FRITZBox 7050) running, and I can switch back to that connection - no problem.

Good luck to everybody else affected.

TThank you EricDY my wifi connection was driving me close to insanity! I know you posted two years ago but has helped me greatly!! Thank you

Sheer brilliance!!! Thank you so much!

This also worked for me on a work wifi system where you are not able to reboot the modum.

Good job! Thank you, worked like a charm.

This is what worked for me. Except I may have screwed things up worse. Currently a nomad roaming through Europe so I am getting lots of new wi fi connections every few days. The steps are as follows.

• Step 1: Make sure your phone is connected to the same wi fi you want your mac to be
• Step 2: Go to Network Preferences / Advanced
• Step 3: Go to the TCP/IP tab
• Step 4: Change the configure IPv4 tab to “using DHCP with manual address”
• Step 5: Copy the exact numbers from your phone onto the manual settings. Make sure that you change the last digit on the IPv4 address
• Step 6: Your wi fi needs to be switched on and off. You can do this in the network preferences tab, next to the status bar
• Step 7: You should now be connected

Hi

I tried everything several times, and nothing worked for me, restart modem, I deleted the com.apple.alf.plist file, created a new location on Networks, deleted the keychains, etc... and the only thing that worked for me was to change my wifi name and password.

Simply deleting one file - the com.apple.al.plist in Mac HD/library/pref/folder worked for me - many thanks everyone for sharing your solutions. My issue was just that my macbook pro self-assigned every time I wanted to go online - I could at least get online if I waited for around 30 seconds but it was frustrating.

Thanks Festee

Thank you Thank you 🙂 i have tp-link router N600 and i did what you sagest but without factory reset ..this work with me.

Regards

Jim_ Crawford, you're a rockstar! I tried absolutely everything on this board. Took me hours and nothing worked. I doubted this would work too ...but it did!! Thanks so much!

I had this problem on-and-off for a while.

But I have finally decided that the problem is not mine. What appears to be happening, is that the internet provider system (not my router) was going down intermittently. But Apple Mail misinterpreted that as an error in the Mail system.

But there is not problem at all. Now all the tourists have gone, and the internet provider is not overloaded, everything is fine.

R

This happens to me all the time. After fiddling with the above advised fixes for about 40 minuets and repeatedly restarting my computer something usually works but no single solution seems to work consistently or immediately. However, I have noticed a pattern to when it occurs. I only have this problem if the last wifi network I have connected to was at my apartment and then I subsequently attempt to connect to the wifi at a local coffee shop. I have found that I do not have the problem if, after working from home, I turn off the wifi and shut down the lap top completely. If I then boot my computer at the coffee shop and physically turn on the wifi I do not have the problem. I do not know what causes this problem. However, i have found that the problem does not happen if I have shut down the wifi after using it at my house. Best of luck.