SOLUTION: Macbook connects to router, but not internet
This issue has driven me absolutely crazy, but here's the solution that worked for me...I hope it works for you.
Issue # 1: Macbook Pro would not connect to Netgear router. By changing the TCP/IP settings in the Network Preferences window to Manual, I was able to connect to the router, BUT still not able to access the internet.
Settings:
Configure IPv4: Manually
Iv4 Address: 192.168.1.x (for your router it will be different if Linksys, Netgear, etc.)
Subnet Mask: 255.255.255.0
Router: 192.168.1.1 (again, this will be different depending on the router).
HOWEVER, the above is meaningless, because while it connects to the router, it will not ALWAYS provide internet access.
THE REAL SOLUTION:
1. Turn off Airport
2. Leave the "Configure IPv4:" set to Using DHCP - this should be the default.
3. On the AirPort tab in Network settings, UNCHECK " "Remember networks this computer has joined"
4. Highlight your router in the Preferred Networks: list, and remove it (click the "-" sign under the list
5. Apply settings
6. turn on AirPort, Add your router if not already there, and that should do it.
The above steps should not need to be repeated each time. Once should do it, but if not, at least it's better than restarting the router each time, which essentially has the same effect as the steps above.
Apparently, there's a software bug whereby if the Macbook finds an available IP address on the Router, it remembers that address. That's fine except that if another device "steals" that address when the Macbook is subsequently not connected, and the "Remember networks this computer has joined" is checked, it's not smart enough to find another available IP address. Instead, it assigns some invalid address beginning with "169.".
By leaving the "Remember networks this computer has joined" UNCHECKED, it will look for a valid available IP address on the router each time.
Good luck!!
