MacBook Air Connects to Comcast Router, But No Internet

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MacBook Air Connects to Comcast Router, But No Internet

Hello there!

I have been experiencing a strange problem for the past few days. I have Comcast as my ISP and they provide a router. I have no problem establishing a connection to the router and I can pull up the router interface on the MBA. However, no matter what I do, I can't get my Mac to be able to connect to the Internet. I can wirelessly connect other devices to the router and they can access the internet without any problems. This naturally lead me to believe that the problem is with the Mac. So I tried to use my phone as a Wifi Hotspot to see if my Mac can connect. It did connect to the phoe AND it could access the Internet.

Well... That confused me even more because if the Mac works with other Wifi Hotspots (at least with my phone) it works.

Here is what I have noticed:

I can ping the Router (Gateway) IP and I get a response.
I do not get a response when I try to ping the DNS address, but I do get a response from the DNS when I ping through my desktop (connected through ethernet).

Here is what I have tried so far:

Set up the network setting (IP/Mask/Gateway/DNS) manually
Turned off the Wifi module and rutned it back on (on the Mac)
Restarted the Mac
Restart the Comcat Modem/Router
Restored the router to factory settings
Changed the wifi channel to all available options on the router
Removed the encryption for the Wifi
Restored (with Time Machine) back to date on which I know for sure I could connect to the internet without any problems.

None of the steps above produced any changes. I am at a complete loss at this point.

I think that about covers it. Anyone have any ideas what might be going on?

I would appreciate any help that anyone can provide!

Thanks a lot in advance!

MacBook Air, OS X Mountain Lion (10.8.4)

Posted on Aug 15, 2013 2:11 PM

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Answer 1

Linc Davis

Level 10

209,739 points

Aug 15, 2013 5:41 PM in response to Ittano

Back up all data before making any changes.

Step 1

Take all the applicable steps in this support article.

Step 2

If you're running OS X 10.8.4 or later, run Wireless Diagnostics and take the remedial steps suggested in the summary that appears, if any. The program also generates a large file of information about your system, which would be used by Apple Engineering in case of a support incident. Don't post the contents here.

Step 3

If you're not using a wireless keyboard or trackpad, disable Bluetooth by selecting Turn Bluetooth Off from the menu with the Bluetooth icon. If you don't have that menu, open the Bluetooth preference pane in System Preferences and check the box marked Show Bluetooth in menu bar. Test. Continue if you find that Wi-Fi is faster with Bluetooth disabled.

From that same menu, select Open Bluetooth Preferences. If the box labeled Discoverable is checked, uncheck it. Click the Advanced button, and in the sheet that opens, uncheck the top three boxes, if any are checked. Click OK. Enable Bluetooth and test again.

If the application called "Bluetooth Setup Assistant" is running, quit it.

Step 4

This step will erase all your settings in the Network preference pane. Make a note of them before you begin, and recreate them afterwards. It may be helpful to take screenshots of the preference pane.

Triple-click the line below on this page to select it:

/Library/Preferences/SystemConfiguration

Right-click or control-click the highlighted line and select

Services ▹ Reveal

from the contextual menu.* A folder should open with an item named "SystemConfiguration" selected. Move the selected item to the Trash. You may be prompted for your administrator password.

*If you don't see the contextual menu item, copy the selected text to the Clipboard (command-C). In the Finder, select

Go ▹ Go to Folder...

from the menu bar, paste into the box that opens (command-V). You won't see what you pasted because a line break is included. Press return.

Reset the System Management Controller.

Step 5

Make a "Genius" appointment at an Apple Store, or go to another authorized service center.

Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional — ask if you need guidance.

If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.

Keeping your confidential data secure during hardware repair

*An SSD doesn't need to be zeroed.

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