Okay, today my friend came across a weird issue on his Mac. His Mac was connected and so was his iPhone and all other devices in the house, to the same access point. But the Mac had no internet access with an exclamation mark on the wifi icon. Despite toggling between the two bands offered by the wireless router, this wasn’t resolved. We even tried toggling wifi on and off, restarting the Mac tna.
It was time to dive into this deeper with some arrogance courtesy of my Linux administration skills! Tried bringing the interface down via Terminal but the problem persisted.
Something overlooked here was that the IP address assigned to his Mac was a 169. address! The home router, like all other home routers runs a 192. address. Set the IP address to be manual instead of DHCP and voila!
p.s. Make sure you do an interface down/up after the manual setting to refresh the interface. Now his Mac works with a static IP.
Login as root to Terminal:
ifconfig en0 down
ifconfig en0 up