I have a Mac laptop running ‘Snow Leopard’ that occasionally will not connect to my home WiFi, even though other devices are connected to the network just fine.

I wrote a small shell script that uses the networksetup command to reset AirPort. If WiFi is still not connected, the script tries to assign the AirPort WiFi network directly. If that doesn’t work, it just resets AirPort again.

#!/bin/bash

AIRPORT="en1"; #may be en0, use networksetup -listallhardwareports to check
WIFI_NETWORK_NAME="network-name"
WIFI_PASSWORD="password"

networksetup -setairportpower $AIRPORT off
networksetup -setairportpower $AIRPORT on
sleep 2

if networksetup -getairportnetwork $AIRPORT | grep -i -a $WIFI_NETWORK_NAME ;
then
    echo 'Connected!';
    exit 0
fi

if networksetup -setairportnetwork $AIRPORT $WIFI_NETWORK_NAME $WIFI_PASSWORD | grep -i -a "Failed" ;
then
    echo 'Failed to connect, just restarting...';
    networksetup -setairportpower $AIRPORT off
    networksetup -setairportpower $AIRPORT on
    sleep 1
fi

networksetup -getairportnetwork $AIRPORT

exit 0;

If this script doesn’t work for you, then I suggest looking inside your routers Wireless settings. My router was set to use a default channel, and this seems to be best practice in terms of wireless signal optimization but for some reason, it was not suitable for my setup. I tried enabling the ‘Auto-Channel Select’ and immediately found it easier to find and connect to my network. As I understand it, this setting will continuously move the WiFi to the channel with least interference, supposedly giving the best signal (but I have seen this refuted elsewhere online).

As an aside, I also came across Appify, which will basically turn your shell script into a Mac App… very useful!

By the way, I’m a shell novice, so if anyone has any advice on more efficient code please leave a comment.