Q: Mac keeps losing internet connection - Resolving Host

First contact your ISP.  You need to confirm that the issue is not on their end.

Change your router channel.  Sometimes this is all you will have to do.

Power cycling the router.  Read the router's user manual or contact their tech support for instructions.

System Preferences/Internet & Network/Network

Unlock the padlock

Locations:  Automatic

Highlight Airport

Click the Assist Me button

In the popup window click the Diagnostic button.

System Preferences/Network- Unlock padlock.  Highlight Airport.  Network Name-select your name.  Click on the Advanced button.  Airport/Preferred Networks-delete all that is not your network.

Place a check mark next to "Remember networks this computer has joined."  Click the OK button and lock the padlock.  Restart your computer.

http://support.apple.com/kb/TS1920 Mac OS: How to release and renew a DHCP lease

No internet connection (wireless)

Check to see if an extra entry is present in the DNS Tab for your wireless connection (System Preferences/Network/Airport/Advanced/DNS).

Delete all extra entries that you find.

Place a check mark next to "Remember networks this computer has joined."

Other resources to check into:

Troubleshooting Wi-Fi issues in OS X Lion and Mac OS X v10.6

Configuring 802.1X in Mac OS X Lion and Later

Non-responsive DNS server or invalid DNS configuration can cause long delay before webpages load

Netspot

How to diagnose and resolve Wi-Fi slow-downs

Pv6 troubleshooting

Mac OS X 10.6 Help:  Solving problems with connecting to the Internet

OS X Mountain Lion: Check the status of your network connections

OS X Mountain Lion: Requirements for wireless Internet access

What Affects Wireless Internet?

Solutions for connecting to the Internet, setting up a small network, and troubleshooting

If using one of Apple's Airport routers, read its user manual or post in its forum area. If using a 3rd party router, read its user manual, contact their tech support department/website or post in its forum area.  Another possible solution - read mammothsuziq response https://discussions.apple.com/message/22082360#22082360

It is not your ISP, my MacBook Poop does the same thing, turning off WiFi and back on again cures it for another 5 to 10 minutes.

I haver a host of Windows machines and Android devices that does not suffer the same issue as this $1500 paperweight.

Full disclosure:  My MBP is a dual-boot machine, running OSX Mavericks on one partition, and Windows 7 Professional (64-bit) on the other partition.

Have experienced similar issues with losing internet connection, though only on certain routers.  When the machine is running under Windows, it doesn't lose connection, though under Mavericks it does - though it takes a while to do so (usually later in the day).

As others stated above, turning off and on Wi-fi does help, for a while.  Tried some of the recommendations listed above, and we'll see if any goodness results.

I have a 2 month old Air which has just started having the same issue. I took it to a friends place and still got the same problem there, all day I've had to disconnect wifi and then connect again, and problem goes away for 10 to 15 mins. It's starting to drive me crazy

Same here. My MBP has worked perfectly with my router since August 2011. Recently it keeps dropping the internet connection, maintaining the WIFI and sometimes it loses both.

Renewing DHCP connects and then blocks. Typing the IP address manually connects to WIFI, but not the internet.

In the beginning it came back on by restarting the machine. Now it doesn't do that anymore. It seems completely random. All other devices, iphone, windows computers, G4, android phones and tablets do not have the problem.

No problems in oter networks. Just my home network. Weird.

Any suggestions?

I had the same problem and so far have solved it by hard-coding my IP and DNS.  No more DHCP.

How did you hard code your IP and DNS?

This resolving host issue is driving me insane. Apple needs to provide some clear instructions on this.

I just talked to Apple and was told to-

1 go to System Preferences- Network- Advanced- TCP/IP- Renew DHCP license- click ok

2 switch off Imac and pull out the cylindrical plug from the back of the imac

3 put plug back in and hold down (p + r + Alt + command keys) until you hear the Imac restart for a second time

It now seems to be working perfectly. This has apparently restored system settings without changing data. Anyway it worked for me.

I was having the same issue, but resolved it after a few days of detective work. Here are the details:

When I upgraded to Yosemite on my MacBook (2010) and iMac (2012) I started having this issue. I also then started having it on an older iMac (2005ish) that is running 10.6 (capped at that OS). The connection worked when hardwired, but not through wifi.

What DID NOT work:

- power cycle cable modem (Comcast)

- power cycle wifi router (Cisco ValetPlus)

- change DNS to 8.8.8.8 (Google)

- cleared System Configuration file

- I also tried a couple of other things that I read about (e.g. option+command+r+p on startup) - none worked

What DID work:

- I started getting curious about my wifi router when I couldn't update the firmware (there wasn't any firmware support past 2011 or so).

- So, I upgraded my wifi router to an Apple Airport Extreme. Once I did this (and power cycled my cable modem again) things started to magically work and the "resolving host" issue went away.

Hope this helps.

My solution which currently works is either

to remove wifi password or

to change encryption method

I've got the same issue, and it has to be a Yosemite software bug.

How i know:

1. Never had this problem before and have noticed it since Yosemite.

2. Two laptops, same problem. One 6 years old, one 1 month old and new model (MB 2015).

3. New laptop can't go to sleep, and it seems like the issue is in the Wifi. When the lid is closed, it keeps getting woken up every 15min from the internet. Have gone through everything with tech and the issue is the Wifi driver. Only way to make it sleep is turn wifi off before closing lid.

4. iPhone and iPad have no issues with the router what-so-ever and the internet on them is perfect.

5. Laptops have the same issue anywhere i go.

6. All friends laptops (note, non mac) have no issues at my place.

7. I know about 20 other people personally who are having this issue with wifi.

Apple, Sort it out!