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MacBook pro connected to a wireless network (not sure about wired) I lose DNS. I still have a functioning connection and as long as I know the ip address of the website, server... for example skype works, ssh name@ipaddress, ....

Things can be working properly and then just quit, Once I was im via skype and lost dns skype continued to work.

This has happened in multiple locations on private and public networks. What does not work/fix it:

  • Resetting router
  • changing dns server on computer or router
  • connecting to another network
  • removing the airport interface and adding it back
  • flushing dns

The only solution seems to be a restart.

A solution to this would be great, but any ideas of this to try would be great. Even a sure way to reproduce this would be useful.

Maybe related question: But this is most definitely not true for me. "if I refresh enough -- 3 to 4 times --, it will usually pull up the site. "

Here are some tests from terminal. Basically this confirms dns in not functioning

vmd17:~ vmd$ ping google.com 
ping: cannot resolve google.com: Unknown host

Trace route to google dns, This works

vmd17:~ vmd$ /usr/sbin/traceroute -n -w 2 -q 2 -m 30 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 52 byte packets
1 192.168.1.1 5.195 ms 2.519 ms
2 67.172.136.1 31.881 ms 9.177 ms
3 68.85.107.121 12.168 ms 10.003 ms
4 68.86.103.41 12.021 ms 9.594 ms
5 68.86.91.1 16.712 ms 12.837 ms
6 68.86.86.210 29.951 ms 25.826 ms
7 68.86.87.218 29.554 ms 42.894 ms
8 75.149.231.70 68.271 ms 68.362 ms
9 72.14.233.77 141.178 ms
72.14.233.85 82.553 ms
10 72.14.238.243 83.381 ms 82.811 ms
11 72.14.232.213 194.387 ms
72.14.232.215 84.837 ms
12 209.85.253.145 100.294 ms *
13 8.8.8.8 101.689 ms 89.694 ms

208.67.222.22 is the ip address of opendns dns server

vmd17:~ vmd$ dig @208.67.222.222 8.8.8.8
; <<>> DiG 9.6.0-APPLE-P2 <<>> @208.67.222.222 8.8.8.8
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached
vmd17:~ vmd$ dig @208.67.222.222 gogle.com

vmd17:~ vmd$ dig @208.67.222.222 google.com
; <<>> DiG 9.6.0-APPLE-P2 <<>> @208.67.222.222 google.com
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached

vmd17:~ vmd$ dig @8.8.8.8 google.com
; <<>> DiG 9.6.0-APPLE-P2 <<>> @8.8.8.8 google.com
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached 
share|improve this question

Variations of this have been reported widely. Have you considered deleting the files under /Library/Preferences/SystemConfiguration?

Here’s how to do it:

  1. Open terminal which is found in Applications > Utilities.

  2. Type the following command:

    cd /Library/Preferences/SystemConfiguration
    
  3. Type the following command to delete the .plist files:

    sudo rm *.*
    
  4. Reboot your Mac.
share|improve this answer
    
I will try this. I remember an old issue with AT&T usb 3g modems needing the same fix. I'll need to keep the old was and do a diff. – Vincent Dec 11 '10 at 14:44
    
This did not solve the problem for me. – Vincent Feb 1 '11 at 22:04

Try some alternate DNS servers, e.g.:

Bway NYC US:            216.220.96.17
Level 3 Communications: 4.2.2.4
OpenDNS:                208.67.220.220

Go to Network Preferences | Advanced | DNS and add one as the DNS for that connection.

You might also ask your service provider (assuming you're using their DNS) if they're having any DNS issues.

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