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I just received a 16" MBP today, and set it up from Migration Assistant as I've done with many Macs successfully over the years. However, it wouldn't connect to WiFi, stating, "Wi-Fi has the self-assigned IP address 169.254.*. and will not be able to connect to the Internet.

This was when I was connecting to previous known networks. However, it WAS able to connect to one open SSID which I'd never used before successfully.

The only fix that has mysteriously worked is to change the MAC address. When I run the command line on this forum post, the WiFi successfully connects. However, upon restart, it once again reverts to self-assigned IP. (I believe Catalina doesn't allow MAC address changes).

Can anyone please help explain how I can resolve this, why the MAC address change works temporarily, and how I can ensure a more permanent solution? It's a custom ordered 16" MBP that took 5 weeks for delivery, so I'd highly prefer not to send it back.

Here are a list of things I've tried:

  1. Resetting SMC/NVRAM/PRAM
  2. Renew DHCP Lease
  3. Remove/delete network
  4. Delete plist/prefs in the SystemConfiguration
  5. Tried two different hotspots
  6. Tried two physically diff networks at home and work
IconDaemon
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IslandMac
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  • Sorry, do you have any recommendations for how I may do that? (what I can assign) – IslandMac Jan 07 '20 at 13:54
  • I wasn't able to connect once I did that. – IslandMac Jan 07 '20 at 14:18
  • I mean there are about 20 devices connected currently. But I also had this issue at work on a diff physical network, and via two diff hotspots via a diff ISP. I did as you noted and just changed the IP address manually and the router. – IslandMac Jan 07 '20 at 14:28

1 Answers1

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I see two possible problems here:

First possibility is that your MAC address after reboot is somehow invalid (i.e. for example set to all zeros). That could make your DHCP server (probably in your home router) reject your request for an IP address).

Check if that is the case by running the following command in the Terminal:

ifconfig en0

Note the line that starts with "ether" - it should have a valid MAC address looking something like f2:23:48:a3:1e:22 or similar.

Second possibility is that the problem is really with your WIFi router / DHCP server and not locally with your laptop. This could happen if your router added the new MacBook Pro's MAC address to a block list or similar.

Check the router's settings and management interface to ensure that the MAC address of your new MacBook Pro is not listed in any black lists - and if you have white listed your old computer, then white list your new computer as well.

jksoegaard
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  • Thanks for that. I checked as you noted, and the MAC address is f8:ff:c5:69:88:8e. In terms of the router - would that be the case on two diff physical networks (diff ISP as well) and two diff mobile hotspots? – IslandMac Jan 07 '20 at 13:10
  • Try setting your MAC address to: f8:ff:c5:69:88:8f. Does that work? – jksoegaard Jan 07 '20 at 13:15
  • I actually don't know how to do that. And is it correct that Catalina will just revert upon start up? – IslandMac Jan 07 '20 at 13:16
  • You wrote in your question that you set the MAC address after start up to some random value, and then it works? - If yes, just set it to the value I have given instead of a random value. – jksoegaard Jan 07 '20 at 13:17
  • Well, ANY version of macOS will revert after startup. It doesn't have anything to do with Catalina. – jksoegaard Jan 07 '20 at 13:17
  • I just used this (can you please show where I can insert the change): sudo ifconfig en0 ether $(perl -e 'for ($i=0;$i<5;$i++){@m[$i]=int(rand(256));} printf "02:%X:%X:%X:%X:%X\n",@m;') && sudo ifconfig en0 down && sudo ifconfig en0 up – IslandMac Jan 07 '20 at 13:18
  • Ah, it wasn't at all clear before that this was the command line you've used. Then I suspect your problem might have nothing to do with MAC addresses at all. Please try booting your laptop, verify that WiFi is not working - then run the following command: sudo ifconfig en0 down && sudo ifconfig en0 up – jksoegaard Jan 07 '20 at 13:19
  • I followed what you noted, still nothing unfortunately. Is this less likely to be an actual issue with the Mac considering it did connect via an unsecured SSID? – IslandMac Jan 07 '20 at 13:49
  • Yes, I think it is very unlikely that it is an issue with the Mac. – jksoegaard Jan 07 '20 at 13:51
  • Okay, now we've tested the first hypothesis. Then to test the second hypothesis - boot the laptop up, and then run the following command: sudo ifconfig en0 ether f8:ff:c5:69:88:8f && sudo ifconfig en0 down && sudo ifconfig en0 up – jksoegaard Jan 07 '20 at 13:52
  • This second command does the same as the command you have that works once after reboot - but it doesn't the MAC address to a random value, but rather to the same as the default value except is says f at the end instead of e. If this works, it definitely sounds like a block list in your router or similar. – jksoegaard Jan 07 '20 at 13:53
  • When I ran that command it did not connect. Still says, "Wi-Fi has the self-assigned IP address 169.254..* and will not be able to connect to the Internet." – IslandMac Jan 07 '20 at 14:01
  • @jksoegaard Interestingly I can't find any vendor for f8:ff:c5 in the MAC databases... – klanomath Jan 07 '20 at 14:15
  • Sorry, please try this: f8:ff:c2:49:88:8e – IslandMac Jan 07 '20 at 14:22
  • @IslandMac No vendor for f8:ff:c2. (To just explain the vendor thing: The first 6 hexdec numbers (the OUI) of a MAC address are assigned to a vendor. E.g. Broadcom, Apple etc. The OUIs of my iMac's interfaces are 68:5b:35 (ethernet) and c8:e0:eb (WiFi) - both assigned to Apple. For f8:ff:c2 or f8:ff:c5 I can't find any vendor.) – klanomath Jan 07 '20 at 14:41
  • @klanomath Yes, I saw the same some hours ago when I checked the MAC. However, it might be that this is just a very recent vendor allocation so it's not yet in the online list of OUIs. Either way, it is not normal for DHCP servers to reject MAC addresses simply because the MAC is not assigned to a vendor - that would be out of the ordinary. – jksoegaard Jan 07 '20 at 15:38
  • @IslandMac It seems a bit peculiar that you have now written to us with two different MAC addresses. Are you sure you write down the MAC address JUST after a reboot, and BEFORE you have run a command to change the MAC? - Also please do not manually change the MAC address before writing it here because you want to keep it "private"... that is not helpful right now. – jksoegaard Jan 07 '20 at 15:39
  • @jksoegaard - it's not peculiar - it was me trying to be somewhat safe by not sharing the MAC initially. However, the second time I shared the correct one. Could it be due to the fact that it's a brand new model - the 16" MBP that's only been out in the wild for a few weeks? Hardware Port: Wi-Fi Device: en0 Ethernet Address: f8:ff:c2:49:88:8e – IslandMac Jan 07 '20 at 22:51
  • Is there any chance that when I initially set the Mac up, I selected the US as the region despite being in Asia? Also, I just got to work, and the only SSID that works is an open, unsecured Guest network. Anything with authentication doesn't work. – IslandMac Jan 07 '20 at 22:55
  • I just spoke with Apple support on the phone. They were very unhelpful and bordering on condescending. They stated that this isn't an issue with the Mac, but rather the ISPs and that I'd need to contact them. I find that highly improbably considering it's two completely different ISPs, on two diff physical locations (work and home) and via two diff mobile hotspots. – IslandMac Jan 08 '20 at 00:12
  • Ok I just disabled the password on an alternative network that previously wasn't working. With no password, it will find an IP and connect.

    What does this likely point to as an issue in your opinion?

     – IslandMac Jan 08 '20 at 02:14
  • @IslandMac Remember for another time - if you state something incorrectly to be safe, please write that you're doing so so that other's don't spend their free time working on something that is incorrect. – jksoegaard Jan 08 '20 at 08:38
  • I don't know if there's a chance that you've selected US. You must know yourself if you did so? - It's not something where it's easy to select the wrong thing. – jksoegaard Jan 08 '20 at 08:39
  • @jksoegaard Noted, thanks for taking the time to work on this with me. I've submitted the machine back to Apple after speaking extensively with Apple Australia and Apple Asia (who were both much more helpful than the US-based support). They believe it may be pointing to a hardware/firmware issue and recommended I submit it for diagnostics. I appreciate your help. – IslandMac Jan 08 '20 at 23:14
  • Please come back and update this when you've got a reply from them - will be helpful for others in the same situation! – jksoegaard Jan 08 '20 at 23:49