MacBook – Wifi Problems when Notebook not connected to power source

Looks like I accidentally stumbled across a solution: if I move my laptop an extra 30cms away from the monitor, the internet connection doesn't trickly away to nothing.

It's probably some kind of interference that is causing the problem, and it seems that keeping some distance between the monitor and the laptop is enough to resolve the issue.

I wasn't able to get my network back by disabling and re-enabling TCP/IP or the Wi-Fi. It seems in my case the computer had gone to sleep with a Juniper VPN connection and when it woke back up the connection had timed out and the routes weren't cleaned up. For me, I had two computers, one working and one not, and so was able to identify the problem after running netstat -rn.

On the computer that wasn't working, I had a destination of 192.168.43.1 with a gateway of link#5. On the computer that WAS working, the gateway for that destination was the mac address of the wireless router, so I removed that route with:

sudo route delete -host 192.168.43.1

After this, I could ping my wireless router and also get back to the internet.

Some people claimed that going to Settings → Network → Wi-Fi → Advanced → Proxies and turning on Auto Proxy Discovery worked for them. I was not able to verify this as my connection was fixed by deleting the 'dead' route.