macOS 27: ifconfig command no longer prints hardware MAC address | Hacker News Reader

macOS 27: ifconfig command no longer prints hardware MAC address

7 pointsluckman21214 comments

Just a quick PSA. A handful of my scripts broke today after installing macOS 27. Turns out they decided to redact the interface hardware ether/MAC addresses, all of them report 02:00:00:00:00:00

(…unless you run with "sudo")

Luckily, you can still get the MAC addresses with

    networksetup -getmacaddress en0

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I filed a bashbug: https://savannah.gnu.org/bugs/index.php?68722

Who needs a physical MAC address when you can just have a spiritual connection to the iCloud?

27.0.1 did not fix it, and I reproduced it on 2 more Macs, one was literally factory reset, just installed a fresh macOS 27, installed Homebrew, installed Bash5, ran ifconfig .... bug reproduced

Interestingly, running `ifconfig` from a Zsh shell still does show MAC addresses

ifconfig is deprecated in modern Linux. Is it not deprecated in BSD? Does Apple not provide the ip(8) command-line tools?

https://manpages.ubuntu.com/manpages/stonking/man8/ip.8.html

No, it seems that iproute2 is Linux-first, or Linux-only: https://en.wikipedia.org/wiki/Iproute2

Sad!

Who says it's deprecated? If it's the same people who think my Ethernet port should be called "enp0s31f6" instead of "eth0", then I'm afraid I do not respect their authority...

The people who maintained it, the kernel developers, the Debian distribution team? You don't accept their authority? I mean, I know this is a MacOS thread, but that's wild.

https://lists.debian.org/debian-devel/2009/03/msg00780.html

16+ years ago

The maintainers barely touched it since 2001.

Fascinatingly enough, this is Conway's law in action. The Linux kernel doesn't break user space, and ifconfig is on the user space side of that boundary. On BSD, they're organized differently, and went a different way.

I can't reproduce this.

It seems to only affect Bash 5.3.20 (Homebrew) - very odd:

    % /bin/bash --version
    GNU bash, version 3.2.57(1)-release (arm64-apple-darwin26)
    
    % /opt/homebrew/bin/bash --version
    GNU bash, version 5.3.20(1)-release (aarch64-apple-darwin27.0.0)
    
    % zsh -c '/sbin/ifconfig en0 | grep ether'
    ether d0:11:e5:1a:27:7a
    
    % /bin/bash -c '/sbin/ifconfig en0 | grep ether'
    ether d0:11:e5:1a:27:7a
    
    % /opt/homebrew/bin/bash -c '/sbin/ifconfig en0 | grep ether'
    ether 02:00:00:00:00:00

it works fine in system bash for me

Yes it works in my system bash too (see above) - seems to be some sort of obscure Bash bug...

Interestingly I can also reproduce it with Bash 5.3.15 from nix-darwin.

I wonder if this is about notarization or something.

Update: I think it's about code signature and how the API responds - which also corresponds to root and system binaries not seeing the issue.

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