Wednesday, 14 March 2012

OSX 10.6.8 Weird Network Problem

OK, so I've had this problem for some time on two Mac Book Pro's.
When I put them to sleep by closing the lid, and then wake them up by opening the lid, all GUI networking stops working and doesn't work until the machine is restarted.

So tonight this annoyed me too much and I decided to investigate.
This is the diagnosis I've done so far.. it points to mDNS, surprise surprise! They are both running 10.6.8 and have had all firmware updates etc applied. Although they were manufactured about a year apart, they both have Broadcom 57765-B0 network cards.

The logs show this:

Mar 14 23:12:43[36]: 2012-03-14 23:12:43,366  INFO [RuntimeAnalysisMonitor] [] - Memory Analysis (runtime)>> Allocated: 29256 kb >> Free: 9270 kb >> Max: 126912 kb
Mar 14 23:12:43  mDNSResponder[43]: *** process 43 exceeded 500 log message per second limit  -  remaining messages this second discarded ***
Mar 14 23:12:47: --- last message repeated 2 times ---
Mar 14 23:12:46  mDNSResponder[43]: ERROR: mDNSPlatformReadTCP - recv 74 got CLOSED 435000 times
Mar 14 23:12:46[36]: 2012-03-14 23:12:46,885  INFO [RuntimeAnalysisMonitor] [] - Memory Analysis (runtime)>> Allocated: 63424 kb >> Free: 40257 kb >> Max: 63424 kb
Mar 14 23:12:46[36]: 2012-03-14 23:12:46,978  INFO [Live Status Collector thread] [] - Cleaning all expired Live Status messages
Mar 14 23:12:47 mDNSResponder[43]: *** process 43 exceeded 500 log message per second limit  -  remaining messages this second discarded ***
Mar 14 23:12:54: --- last message repeated 6 times ---
Mar 14 23:12:54  iChatAgent[349]: [Warning] IMDServiceSession <AIMServiceSession: 0x100123700>: Want to connect to, but it is NOT up
Mar 14 23:12:54  mDNSResponder[43]: *** process 43 exceeded 500 log message per second limit  -  remaining messages this second discarded ***

But the following tests work:


Non-authoritative answer: canonical name =

telnet 80
Connected to
Escape character is '^]'.
HTTP/1.0 400 Bad request
Content-Type: text/html

<h2>Client sent a bad request.</h2>
Connection closed by foreign host.

Now.. this shows that networking is up, and we can connect to port 80 on a webserver, ie we can surf the web.... 
But everything in the GUI fails to connect to networking.. ARD, afp, web, mail, ical etc.

The solution is to force quit the mDNSResponder either from the command line with:

sudo killall mDNSResponder

or to select the mDNSResponder process in Activity Monitor and force quit it.

Because it's managed by launchd it will automatically relaunch, and when it does networking is instantly restored.

I haven't yet worked out why it goes wrong, but at least I know where the problem is...

Next step is to diagnose the wake up process!

Tuesday, 6 March 2012

Long time no update

When I started this blog I intended to update it regularly like I guess most people who start blogs do!
However, it's been a busy couple of months and I haven't posted anything, which I view as somewhat of a failure on my part.

This doesn't mean I haven't had anything to blog about, just not enough time given other commitments to actually sit down and write stuff. It sometimes amazes me when I think about how much time people must spend writing blogs!

So what I have been up to?
For a start, a lot of time has been spent on house maintenance. It's amazing how many things you can find wrong with a 200 year old house when you start looking! Staircases about to fall down, leaking baths, dodgy electrical installations, the list goes on.
I now have a new moral to this... don't start looking!

From the tech side, I've been doing a lot of stuff with Cat DV recently, and some more with ResourceSpace, so I'll try and get round to adding content very soon.

Hopefully the house renovations are on hold for a while, but you never know what's round the corner.