A Mac DNS problem

[RogerS]

SWMBO's websites have been migrated to a sensible provider but one of them kept resolving back to the Company That Has No Name. The name servers were all updated at the same time and the other two websites worked fine. Using my router to do a DNS lookup from its' control panel confirmed the misrouting.

Did the usual. Switched the router off/on...even though it is set-up to point to my ISPs DNS server... no joy. Still pointing erroneously. Suggests that Zens' DNS server not updated but Zen support (how refreshing isn't it to get someone on the end of the phone (a) within seconds of making the call and (b) knowing things) checked and their DNS server pointed to the correct point. I got Steve M to check the site and he could see it OK.

Switched the Mac off/on. No joy. Cleared browser cache. No joy. Tried a different browser. No joy.

Rebooted the router from its control panel. Still nothing. Notice router has changed back to Automatically get IP address from ISP and so force it to go straight to Zen's DNS servers IP address. OK...DNS lookup gives the right info now.

Back to the Mac. Still no joy. Mmmm....maybe the Mac has a dns cache inside it. Use dscacheutil -flushcache from the Terminal. Bingo.

 

[cutting42]

Try a PC

 

[RogerS]

I spoke too soon. That site is still u/s. I'm stuck.


Where's that PC? :wink:

 

[cutting42]

Actually I was lying, DNS errors on PC's can be a nightmare as well. Check and clear out the hosts file, no clue where it might be on a Mac tho. That has saved my bacon a few time although more about lookups and IP addresses usually.

 

[RogerS]

I think that that is what the terminal command I gave does but I have to say I am stumped. For some reason, the Mac I'm using constantly tries to access the old host address. I can navigate to the correct site using another Mac..same router. I've run Onyx and cleared out the obvious caches but still something is wrong.

Well and truly stumped.

 

[Chris Knight]

Nambench works for me

http://code.google.com/p/namebench/

 

[RogerS]

I'll give that a go later on, Chris. But as you can see it's narrowed down to a problem on the Mac. Any suggestions very very welcome.

Heh..Heh!! Just tried Namebench amd guess which DNS server came out tops? Zen!! The one I'm currently using. Dead chuffed. Now about this pesky Mac....

 

[special bone]

Can you try using a different web-browser on the Mac? That would narrow down whether it is a Mac problem or a web-browser problem.

If it was a PC, I would have suggested flushing the DNS but I don't know how to do that on a Mac. However, a quick search of Google will probably tell you how to flush the DNS on a Mac.

 

[RogerS]

Hi sb, I've tried several different browsers and also flushed the DNS cache. So it seems local to my Mac.

 

[Chris Knight]

Could try this
http://www.dnschanger.com/

It worked for someone here

http://discussions.apple.com/thread.jsp ... ID=7437464

 

[RogerS]

LOL...very droll!

I thought I'd cracked it last night as I ran repair permissions. I did get access to the site. Only this morning, it's back to trying the old IP address and Repair permissions reports nothing untoward.

It is such a strange IP routing issue. I can browse to my router and do a DNS lookup there of the website. The correct IP address is returned. This tells me that my router/ISP DNS server is OK. I know that also from being able to acess the site from another mac attached to the same router.

But on my Mac, when I run traceoute I can see it go off to try and access the old site. Bizarre.

 

[Chris Knight]

LOL...very droll!

???

 

[RogerS]

Tried dnschanger and I'm not infected! No dodgy codecs downloaded here..no, sirree. :wink:

 

[RogerS]

I think that it is an issue with one of Zen's DNS servers. The name is not resolving when I run a tcpdump.