10.7.3 DNS periodically stops working - "Server not found" error

Safari 5.0.1 or later: Slow or partial webpage loading, or webpage cannot be found

Did you try changing your DNS settings, as suggested in the article?

This happens to me a LOT. Changing my DNS settings has no affect. It's a Lion/WiFI/Airport problem, niot a DNS problem.

I wish I could do more than say "Yes, you're right" but I have no fix. Except to say now I'm using 10.7.4 and the problem still occurs. 😟

Try this:

http://www.makingitscale.com/2011/fix-for-broken-search-domain-resolution-in-osx -lion.html

I haven't seen the problem since I made that change

I can report that I, too, am having the same DNS issues on my Macbook Pro with Lion - but connected via Ethernet, not WiFi (WiFi is turned off). It fails to resolve the same local hostname that was working for the past few weeks and nothing I have done has fixed the problem today (I am accessing my local hosts via IP address). I have tried rebooting, changing my DNS server, flushing my DNS cache, but no dice. My iMac is connecting fine to the local hostnames as are Windows machines. /shrugs

I am having the same issue on my Intel based iMac running Lion 10.7.4, primarily with my Exchange server address-either through outlook, Safari or Chrome. DNS will not resolve the URL. I can't ping it using the URL, but can see it using Terminal. If i use the numeric address, I can ping it and access it, but can't make a secure connection. If I reset my DHCP, sometimes it will resolve the URL, other times it spontaneously works. Apple refers me to Microsoft, Microsoft refers me to my Exchange host and my Exchane host refers me to Apple. All of my PC's, iPhones and MacBook (also running Lion 10.7.4) can access this secure server over my Time Capsule based LAN. Clealry a DNS issue on my iMac.

Same problem here - I have an old Macbook running 10.5.8 and a new mid 2021 macbook pro running 10.7.4.

For certain webpages (e.g. www.macinstruct.com) the new mid 2012 macbook pro will not be able to open the page - it does not happen all the time, but very regularly. The old Macbook does not have the issue - I can opne the page from it at the same time as the new one is reporting it cannot find the server.

I cannot ping using the domain name either and to me also the issue looks like a DNS problem.

Wifi set up is identical on both machines and both are using the same router.

This seems a very basic issue to be unresolved for so long - I have a support call in and will update this thread if anything comes from it.

On my iMac, I ended up putting in the IP address for the Exchange web server, and it works fine. Not sure what the issue is, but it is strange. If I ping the URL using terminal, I can get to it, and it resolves the URL to the IP address.

I have the exact same issue with my September 2011 MBP running 10.7.4. For the last 5 minutes, I cannot resolve google.com for love nor money with any application at all. Other domains are fine. Some Facebook hosts are not resolving. This happens both on wired and wireless connections. tcpdump will show my Mac querying my preferred DNS servers (in this case Google's resolvers), but no reply comes back. I suspect that the resolvers are responding, but that the problem is at layer 2, meaning tcpdump is never going to see the response packets and the application layer will have no access to the response data. It has nothing to do with which resolvers I'm using. It happens with my ISPs resolvers, Google's, OpenDNS, Level(3), etc.

Switching from wired to wireless will fix it. Firing up a VPN tunnel will fix it. Basically changing interfaces will do the trick.

Its horribly frustrating.

FWIW, I am still seeing this problem on my Early 2008 15" MBP running 10.7.5.

However in my case using either Safari 6.1.1 (or ping with a name) will occasionally hang for 20-30 seconds, but pinging a straight address works fine.

But in my case Chrome 32.0.1700.107 will resolve names just fine.

Wow this is an annoying bug. 😠