Need help, please, with a MacBook Air that refuses to connect to Wi-Fi at the office

Tech Support
,
1

OK, MPU experts, I need some major help here. This is kind of a long setup, so bear with me.

I have a 2020 MacBook Air with the M1 chip. It’s running macOS Monterey (12.3.1). At home and everywhere else, it connects to Wi-Fi just fine.

However, when I take it to my office, it will recognize all the various Wi-Fi networks around, but it will not connect to the workplace’s network.

Now, here’s the interesting part. In my office I have an older Mac mini that is running the same OS, and it connects to the chosen Wi-Fi network just fine. In another part of my office I have a 2013 MacBook Pro running Catalina that also connects just fine.

I have done all the usual suggestions found in various web sites: rebooted, “forgot” the network and selected it again, deleted various preference files, reset PRAM and NVRAM, etc. I’ve talked to our IT folks, and although they don’t support Macs they have gamely tried to help. They are as puzzled as I am.

Resetting the router is probably not the solution because we’re a HUGE wireless network covering four buildings made up of 23 stories. Plus, since every other Apple device I own connects with no problem, I doubt it’s the router or any of the other nearby wireless points. Many people who work near me also connect their Apple devices to our network with no problem. Thus, it seems to be something about this particular MacBook Air.

A couple of other notes. I have copied all the network settings from the Macs that do connect and plugged them into the errant MacBook Air. No luck. The message I get is simply that the network can’t be joined. This isn’t an issue of usernames or passwords. I don’t even get to that point. It just seems to try to connect for a minute or two and says it can’t be done.

I also created a new administrator account to see if I could connect using that user account. Nope.

So, I’m really confounded about all this. Does anyone have any deep ideas that might help get this laptop into a more cooperative mode? I suppose I could always do a “nuke and pave,” but that is certainly the last thing I want to have to go through.

Thank you all for your ideas. I appreciate any insights you might have, even if I’ve already thought of it.

Cheers!

2

If I may ask, have you tried deleting the wifi network and adding it back?

You may want to check Set Wi-Fi network options on Mac - Apple Support

3

Can you share wifi from one of the Macs that works to the one that doesn’t work?

4

Under System Preferencers/Network/ TCP-IP under advanced, make sure you are configured Using DHCP. Then renew the DHCP Lease

image
image1240×442 51.5 KB

If that does not work then try setting it to “Manually” set the IP address and choose something like 192.168.1.250

5

if any of the above suggestions still fail, try running Apple diagnostic and resetting NVAM , PRAM and SMC

6

In System Preferences/Network/Advanced, triple check the TCP/IP settings, especially authentication method and DHCP lease. See especially rkaplan’s post; that is where a lot of drop-offs happen, because the Mac wants a new lease.

Go through the complete Diagnostics process, with verbose logging (not what the panel calls it now, but you want the log). The log sometimes offers a clue about where the process goes pear-shaped.

At an agreed upon time with IT, have them to capture a live log as you attempt a clean log in. That too often provides a clue.

7

They wouldn’t be doing things like permit or deny listing MAC addresses, would they?

How is the network being secured? Does your Mac need a certificate to be installed?

5 Likes
8

I know you involved IT and they should have checked, but they should ensure your device’s wifi MAC address hasn’t somehow made it onto a block list. This used to happen to me very occasionally when I traveled a lot, on hotel wifi. For no apparent reason, the hotel’s service provider had to manually unblock me. You will probably have to provide them your MAC address in order for them to search the block list.

2 Likes
9

There’s noting worse to remote diagnose than “WiFi not connecting”. :smiley:

Let’s try to boild down the problem to the possible causes:

  • Mac hardware: obviously not the problem, since you can connect to networks.
  • WiFi hardware: not the problem, since hundreds of devices are accessing the network
  • Authentication: since your “IT guys” were involved, you should be choosing the right method, even if it’s RADIUS or else. I guess they checked DHCP.

Do you have a custom DNS (Cloudflare, Google)? If yes, get rid of it.

So, it seems that your Mac and the network refuse to talk to each other.

Try to change the MAC on the Mac :-D. Maybe going into the network with a different MAC will do something. Networks recognize devices by the MAC, so changing it will create a “new” device for the network.
If it fails: we can exclude certain stuff
If it works: we know where to go from here

To change the MAC:

  • Check your current MAC (Network settings, Advanced)
  • Check which name the WiFi adapter has. Usually it’s “en0”. To confirm, in Terminal: “ifconfig”. When you have a lot of network stuff installed, the name could have changed. This step just rechecks that “en0” is assigned to the MAC above.
  • We assume en0 is correct. If your WiFi es en1, work with that name for all the stuff below.
  • Below the entry for “en0” there’s a line like " ether 73:8e:3c:b9:22:26". That line, under “en0” is the important one. Your computer goes with this MAC to the network, tried to connect and get an IP adress from DHCP (if you have a line like “inet 192.168.1.133 netmask 0xffffff00 broadcast 192.168.1.255”) below it, it was successful.
  • to change the MAC (" ether 73:8e:3c:b9:22:26")
    • In System Preferences->Network->Advanced->Hardware set configuration to “manual”
    • Dissasociate from the network with “sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -z”
    • change the MAC with “sudo en0 ether 73:8e:3c:b9:22:xx” (use the MAC your Mac had and add or substract one, just make it different)
  • Check the change (“ifconfig en0 | grep ether”)
  • Try to join the network

Don’t worry about all that stuff, if you reboot your Mac, everything gets back to “normal” (Except: "System Preferences->Network->Advanced->Hardware set configuration to "automatic)

Do you get a connection with a spoofed MAC?
If not:

  • We can rule out some authentication issues (DHCP,…)
  • We can think of removing network configurations from the Mac
    If yes:
  • talk to the IT guys. You didn’t change hardware/software and a new MAC is giving you access. MACs are supposed to be unique, but sometimes there are dual MACs. Or is the router/DHCP having an issue with that MAC? Let them check DHCP entries and logs for your MAC. And no, it’s not a “Mac support”, it’s basic network support.
10

Yep, tried that, along with the tips on the Apple Support page. It’s truly weird how it won’t connect.

11

Hadn’t thought of that…but is it possible to connect via Wi-Fi on Mac 1 and share that connection with Mac 2? Worth looking into. Cool!

12

I will have to try changing the MAC address. That’s quite intriguing. Thank you Lara! (I agree, diagnosing this type of problem is a real pain.)

Mpacker, one of my first thoughts was that perhaps IT threw a switch to prevent personal laptops from connecting to the network, but IT says they haven’t done that. But I’ll follow up on the block list idea. Thanks!

@Medievalist, I’ve run the diagnostics, but I have to admit that I don’t know what to do with all those various files or the info in them. I may need to see if I can find a tutorial on how to use the results. But I appreciate you giving me an idea of comparing logs with IT. Will follow up on that one!

@ACautionaryTale, IT says there’s no permit/deny going on. The network uses WPA2 Enterprise, and I don’t think any certificate needs to be installed. But that’s a good thing to check. Thanks!

@rkaplan, I hadn’t thought of setting a manual IP address. I will have to give that a try. Seems simple enough…Grazie!

I really appreciate all the ideas, even the couple I tried already. Thank you so much. If I figure out a solution, I’ll try to post it here so others can benefit perhaps. Cheers!

2 Likes
13

That’s what I meant with “the IT guy should know that”.

Other avenues:

  • macOS/RADIUS sometimes don’t agree on each other. Instead of clicking on the network in the WiFi pull-down menu, select “Other notworks” and manually specifiy the network type and login credentials.
  • Also check keychain (search for network name) if anything is stored there. Remove it.
14

I was going to suggest this but maybe try booting in safe mode and see what happens.

15

Certainly not! For two reasons:

  1. With the router at 10.0.0.1 and the subnet mask of 255.255.255.0 you would need an IP address of 10.0.0.2 through 10.0.0.254.
  2. If you happen to pick an address already in use, there will be an angry employee somewhere as well as getting the wrath of the IT department.
1 Like
16

Correct. IP needs to be within subnet mask. If manually assigned: please check that with IT. Usually they have a range not assigned by DHCP for those.

17

Agreed - 10.0.0.* happens to be an address for my home network with an Orbi system; I was guessing at the more standard 192.168.1.* but it should something compatible with the network he is using.

I doubt choosing an IP address for testing purposes will wreak havoc. It would be pretty unusual for a corporate IT network to be defeated so easily if someone else is using it. Likely the router compares both MAC address and IP address so there would be no harm.

18

My son had a similar problem with his MBA and I resolved it by creating a new location:

image
image944×220 12.8 KB

Worth a try…

19

The specific authenticaiton protocol may be important too (WPA2-Enterprise has several methods)

20

Well, I’ve tried all the suggestions everyone has been so kind to offer. I really appreciate the time people put into this. Unfortunately, none of the ideas have been fruitful (slight Apple pun there). I think I will end up settling for using my iPhone as a personal hotspot when I need to be online at the office. I could reinstall the macOS, but who knows what new issues might crop up after that. Plus, there’d be an awful lot of restoration to do. It might be best to let this sleeping dog lie.

Thanks again, MPUers!