Wi-Fi off while the dock has a network

I’ve got a CalDigit TS5 on my desk with a network cable in it, and I wanted Wi-Fi to turn off while I’m on the cable and back on when I’m not.

Checking for the dock isn’t enough, a dock with no cable or a cable to a dead switch shouldn’t leave me with no network.

So Wi-Fi goes off only when the dock’s Ethernet has a link and an IPv4 address.

The device name can change, so we’ll find it by the dock’s MAC address, which you can get from networksetup -listallhardwareports, and add the following to ~/.local/bin/dock-wifi-toggle.

#!/bin/zsh
DOCK_MAC="aa:bb:cc:dd:ee:ff"

wifi=$(networksetup -listallhardwareports | awk '/Hardware Port: Wi-Fi/{getline; print $2}')
dock=$(networksetup -listallhardwareports | grep -i -B1 "$DOCK_MAC" | awk '/Device:/{print $2}')

if [[ -n "$dock" ]] && ifconfig "$dock" 2>/dev/null | grep -q "status: active" \
   && ipconfig getifaddr "$dock" >/dev/null 2>&1; then
  want=off
else
  want=on
fi

current=$(networksetup -getairportpower "$wifi" | awk '{print tolower($NF)}')
if [[ "$current" != "$want" ]]; then
  networksetup -setairportpower "$wifi" "$want"
  logger "dock-wifi-toggle: Wi-Fi $want (dock=${dock:-none})"
fi

Changing the Wi-Fi power is a network change too, so the script starts again right after it runs, and the check before we switch means that second run does nothing.

We don’t need a timer to run it, /Library/Preferences/SystemConfiguration changes on any network change, so we can point a LaunchAgent at it with the following in its plist.

<key>WatchPaths</key>
<array>
  <string>/Library/Preferences/SystemConfiguration</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>ThrottleInterval</key>
<integer>5</integer>

Pull the cable out and Wi-Fi comes on, plug it back in and it goes off once DHCP is done.

You can watch that with the following command, with the full path because log is a builtin in zsh.

/usr/bin/log stream --predicate 'eventMessage CONTAINS "dock-wifi-toggle"'

It also fires when the laptop wakes

After a few weeks I took a look at the log and there were 52 changes in 14 days, 24 of them from a single day, in pairs 5 to 10 seconds apart.

2026-11-04 13:32:20.700 dock-wifi-toggle: Wi-Fi on (dock=en11)
2026-11-04 13:32:31.006 dock-wifi-toggle: Wi-Fi off (dock=en11)

Every pair I checked starts 5 or 6 seconds after a wake in pmset -g log, including the dark wakes where the screen stays off.

The link on the dock’s Ethernet bounces when the laptop wakes and the address goes with it, so for a few seconds the cable has no network.

The script does what I told it to do, Wi-Fi on, and off again once DHCP is bound.