Jul 31, 2014 Did you install any software that intercepts network traffic like Little Snitch or X3 etc.? Do you use some kind of proxy or firewall? Also, I found out that nslookup localhost is no good for checking name resolution troubles; use ping instead to check if localhost is resolved correctly. Discuss: Little Snitch caching DNS information: How to clear Sign in to comment. Be respectful, keep it civil and stay on topic. We delete comments that violate our policy, which we encourage you.
I have a 17' Powerbook, OS X ver. 10.3.9. Every few hours or so, my DNS resolution stops working. I can still ping and traceroute all over the Internet, but cannot resolve names.
When DNS is working, I can telnet to port 53 of the DNS server I am using and I'll get a banner back from the DNS server saying I am connected to port 53. I can also resolve thru nslookup, of course.
But when the DNS stops working, I can still ping the DNS server, but cannot telnet to port 53, or resolve names, or use nslookup. (nslookup cannot reach **any** DNS server I try to resolve through!) It doesn't matter what I use for my DNS server. It sounds like something is blocking outbound access to port 53 on the Internet.
But, I also have a Windows machine on the network which can use DNS fine. If I swap the IPs of the mac and windows box, the problem stays with the mac, not the IP address.
I also have no oddball software on my mac, am using mostly default settings.
Any ideas??
When DNS is working, I can telnet to port 53 of the DNS server I am using and I'll get a banner back from the DNS server saying I am connected to port 53. I can also resolve thru nslookup, of course.
But when the DNS stops working, I can still ping the DNS server, but cannot telnet to port 53, or resolve names, or use nslookup. (nslookup cannot reach **any** DNS server I try to resolve through!) It doesn't matter what I use for my DNS server. It sounds like something is blocking outbound access to port 53 on the Internet.
But, I also have a Windows machine on the network which can use DNS fine. If I swap the IPs of the mac and windows box, the problem stays with the mac, not the IP address.
I also have no oddball software on my mac, am using mostly default settings.
Any ideas??
I'm using Little Snitch as an outbound firewall, and have noticed the AssetCache process is trying to make outbound connections to non-Apple destinations, such as www.geek.com and b.voicefive.com. This seems very suspicious... any explanations?
>> I did some nslookup/whois, and all the IP addresses are owned by either my ISP, or by Akamai CDN... sounds like it's accessing a content distribution network, not so suspicious after all. Maybe the reverse DNS zones are out of date.
Message was edited by: BobF4321
Mac Pro, OS X Mountain Lion (10.8.2)
Little Snitch Nslookup Server
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