10.13 High Sierra Wi-fi issue

I had the same issue you guys have and after serious hours of troubleshooting I figured that my AT&T router has a feature called Band staring. For the feature to work you have to setup both band SSIDs 2.4Ghz and 5.0Ghz) with the same name, So the computer will decide to connect to the band that offers a better signal levels. Apparently High Sierra does not handle this very well and gets confuse. As a temporary fix, I have set diferent names for the SSIDs and now I can connect to either band with no issues. It will connect at wake ups or reboots. Apple still need to come out with a solution for this.

Hopefully this would work for you guys.

MBP 13’ mid 2012.

I have resolved the issue. I had to install a new hard drive on my macbook pro anyways. Then I first installed a new copy of High Sierra from an installer. Wifi only occasionally worked, when the computer was directly next to the router, as others had reported too. Then I erased everything and installed all my data directly from the time machine. Wifi was not working. Then over that I installed a fresh copy of High Sierra. Wifi was not working. I cleaned the list of Wifi addresses except for the address in my house. Then I moved the following files in /Library/Preferences/SystemConfiguration/ to the trash as had been reported by others. I also deleted an old file there preferences.plist.old. When I restarted the computer the problem was gone and Wifi is since then working well. However, doing this it is recommended to back up all data.

com.apple.airport.preferences.plist

com.apple.network.eapolclient.configuration.plist

com.apple.wifi.message-tracer.plist

NetworkInterfaces.plist

preferences.plist

Okay, check it out, I fixed this issue with a bit of serious thought and a good work around. Although a permanent fix this might not be, it does work. First off I had to think about how the fk does apple work in the first place, everything we see on our desktop and runs is basically happening from terminal commands. So I figured what is the terminal command to join a wifi network, once I had that working, I figured I could use apple script to launch the command at startup. Since high sierra does try to attempt to join the network during boot up, I had to add a delay, in my case 45 seconds before it (the script) tried again. Well long story short it works. below is the Apple script command I use. I cheated a little and let Geektool do a OSA run on the script, but still it doesn’t matter how you want to have it start up.

EnJoy 😀

the 45 is how many seconds to wait until executing the script, the rest should be self explanatory.

I know it isn't nice to have your password as plain text, but hey, you have to type it in each time anyway.

######################apple script####################################################

set input to "45"

delay input

do shell script "networksetup -setairportnetwork en1 yourhiddenSSiD yourpasswordforhiddennetwork"

Edit:

I just realized it isn't necessary to add the password for rejoining a saved hidden SSiD network.., So you can leave that out.😁😁😁

Had the same problem with an iMac (late 2015), went through the same steps. Actually, it was VPN Unlimited that was interfering, trying to connect constantly and aggressively even though not activated.

Hey I found a helpful youtube tutorial if you search "sierra wifi fix"...should be the first option but the user's name is "oowwnn" and the video is called "unsupported Mac Sierra install wifi fix". The user has a link in the video description to a script that he made. I was having this issue and I strongly think it's a Broadcom wifi card driver incompatibility issue. I have a 2011 Mac as well. Basically Apple did nothing to help my issue as usual and I had to find a user that wrote a script to update the driver...this worked for me. Hope this helps and hope even more that Apple will fix their compatibility issues before pushing out new OS updates. Relying on their customers to fix bugs is getting outdated.

Have you disassociated (airport -z) your network?

Made sure you're not close to other overlapping channels, and all that jazz?

Followed by checking for removal of it from your Network settings> and a reboot... then rejoin.

Found a solution.

Same issues that everyone here is reporting.

I am on ATT giggabit.

ATT had me update the SSID from the default SSID and that instantly fixed all of the connections issues.

Try updating your SSID and PW in your router settings. Or you can contact your net provider to do it for you.

I did the workaround of advertising my Wifi SSID- This happened back when Sierra came out and only after an update did it re-connect to a hidden Wifi SSID on my iMAC mid 2011 - Funny the MacBook 2015 had no issues nor my iPADS.

Did they forget to test on an older iMac?

All the solutions, deleting files etc, worked only temporally until I restarted the computer or the computer was asleep. However, I have a second account on my home wifi. When I chose that and logged into that account, it stayed logged in. When I restarted the computer it was still ok. I deleted the old account in network settings. When I chose that account again to log in, there was the message that the password was invalid even the password was the correct one. I have no idea why that is happening. But using the second account seems to have resolved the issue.

It is clearly a problem caused by Apple in High Sierra, which I expected was fixed by 10.13.1 but no. I tried all the possibilities reported here. But as I reported earlier, the only thing that worked was to use a different wifi username and password for the same (AT&T) router, which I had already created some time ago and deleting all the former wifi accounts in system preferences, which are usually remembered.

When I tried using my original wifi account again, the problem came back. So I switched back to the new account I was using. Also when traveling other wifi accounts were just fine.

I did unhide the SSID, it still wouldn't work after reboot. I then deleted the wireless network from the network preferences. I think I rebooted again, rejoined the network and for 4 to 5 wake from sleep, it is still finding my wireless network. This has been the most difficult upgrade I have ever done. I just hope it keeps working. I clean installed High Sierra on an external drive and it worked until I put the hard drive in the 2011 iMac. It seemed to have some problems after I made it the internal drive. I have heard that some have problems with photoshop CS6. I had one problem, but it has worked OK since. I won't install any more updates because I have no idea if apple will break something else. Right now, I am not real confident in what they are doing. Thanks everyone for the suggestions.

Hi Buddy,
Try Turning off the Bluetooth, it is working for me.

non need to play with parameters 😉

10.13.2, released last night appears to have fixed it for me.

Hopefully this fixes it for everybody else

Good luck

Changing from 5GHz to 2.4GHz solved it for me.