In crowded areas, these details help you find the best router to connect to. Keep this function open as you move to different areas.If you’re setting up a router yourself, this function lets you find the least crowded channel. You’re looking for the best signal under quality with the least amount of noise under signal.
These are the same type of logs the Wireless Diagnostics creates. These are the logs you’d send to a support person when you have a problem.
This feature looks at all the wireless networks it sees and looks at how you can connect to them. If you aren’t sure what’s wrong with your connection, this is where you’ll find the details you need to fix your problem.
If you unplug your router and plug in your Mac, you may need to reboot your cable modem so it accepts the Mac's MAC address.
You'll need to reboot it again if you switch back to your router.
Now it is not getting connected to internet via Ethernet cable but Wireless works just fine.
What happens is when I connect the Ethernet cable it says self assigned IP as shown in screenshot.
One common issue that has affected OS X systems is when network interfaces are issued a self-assigned IP address, even though the system is connected to a network with a properly configured DHCP server.
When this happens, other systems on the same network (often including similarly configured Macs) will be working just fine, indicating the problem lies with the Mac’s configuration and is not a compatibility issue with the networking hardware.
I have tried to manually enter all IPv4 information but doesn't help To reset the firewall, go to the /Macintosh HD/Library/Preferences/ folder and remove the file called "com.plist," and then restart your computer.
After the system boots, you may be prompted to allow incoming connections to numerous programs and services, so accept these for now (you can always go to the Firewall settings and deny or remove entries later on) and then try connecting to the network again.