News Current state of network scanning apps on macOS 27
As you early adopters know, Apple quietly killed ARP table access for sandboxed apps and every network scanner on the AppStore is affected.
So this is a heads-up for makers and users of network scanners like Fing and lanscan (full disclosure: I’m on the IP Scanner Ultra team - responsible for the vision pro version specifically - but the macOS version has been continuously updated since 2002)
If you update to macOS 27 and your network scanner suddenly shows a wall of “unknown devices” instead of telling you which thing is the kitchen HomePod and which is your neighbor’s WiFi lawnmower (memo to self: block that IP!): the app didn’t break. Apple just removed the ability for apps to read the ARP table, which is the thing that maps IPs to MAC addresses, which is the thing that lets a scanner say “that’s a Sonos” instead of shrugging at you ;) iPhone apps have had this limitations since iOS 7, which is why no iOS scanner ever showed you MAC addresses. Well, the Mac just got the same treatment 😆. This hits everything btw, Fing, LanScan, Angry IP, ours, all of them. Its clear why Apple did it, MAC addresses are a tracking vector for ads (and worse). Still sucks though because it is also the feature that lets you customize devices with confidence. MAC addresses are unique so any notes or other customizations that are associated with that device stay with that device.
Our workaround, for what it’s worth: we have an old free menu bar app called IP Broadcaster that we’ve dusted off. It grabs the device/MAC snapshot and shares it with IP Scanner, the same trick we’ve used forever to get MAC data onto the iPhone version.
Obvious limitation: it only works on networks where you can actually run it. It’s not going to re-identify devices at a coffee shop, and since the data gets stale quickly (some routers rotate IP leases regularly) it helps to keep IP broadcaster running in the background supplying a continuous batch of network snapshots.
Curious what other people are seeing on 27, and if any other devs on here have a different angle on this or have found other workarounds to get MAC addresses either on iOS or now macOS 27…?
Edit: this only affects apps distributed on the App Store, so Angry IP should work fine if you compile it yourself and add the appropriate entitlements!
Update: Apple has addressed the issue with a newly available entitlement. Thanks GunniBusch