PortMap causes 100% CPU usage in mDNSResponder

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Log on to network
2. Move to another room - with another airport acting as a network extender
3. I can reset usage by relaunching PortMappe. After relaunch, everything is OK

What is the expected output? What do you see instead?
I see mDNS responder utilising close to 100% CPU on once core of my MacBook Pro.
mDNSResponder repeatedly logs the following to the console during this time:
04/02/2009 07:17:48 mDNSResponder[20] CheckNATMappings: Failed to allocate port 
5350 UDP multicast socket for NAT-PMP announcements 
04/02/2009 07:17:48 mDNSResponder[20] mDNSPlatformUDPSocket: SetupSocket 5350 
failed error -1 errno 48 (Address already in use) 
Quitting PortMapper allows mDNSResponder to settle back to normal usage, error 
logging stops. Restarting PortMapper does not show the problem.

What version of the product are you using? On what operating system? Intel or 
PPC?
1.2 (34) on OS X 10.5.6 Intel MBP

What model and manufacturer is your Router?
AirPort Extreme main router, extended by an Airport Express.

Please provide any additional information below.

I am mapping ports 6942 and 51413 (SubEtha Edit and BitTorrent)

Original issue reported on code.google.com by rog.no...@gmail.com on 4 Feb 2009 at 3:25

[GoogleCodeExporter]

this is actually a known issue of the mDNSResponder that is hard to work 
around. if you encounter it you can 
turn portmap off and on again after 10 seconds or so and the problem is solved. 
the issue has to do with how 
the mDNSResponder opens it's ports. the bugreport filed with apple is 
rdar://problem/6437092 if you want to 
file a duplicate. This also contains a patch for the mDNSResponder to fix this 
issue - i hope the next mac os x 
update will include that. nevertheless i will try to work around this further 
in a next release. 

here is the contents of the bug report in open radar FYI
http://openradar.appspot.com/radar?id=3406

Original comment by dasge...@gmail.com on 5 Feb 2009 at 12:21

• Changed state: Accepted
• Added labels: Type-Defect

[GoogleCodeExporter]

Thanks. I'm happy with the workaround. Hope apple fix the defect.

Thanks for PortMapper too ;-)

Original comment by rog.no...@gmail.com on 5 Feb 2009 at 12:25

[GoogleCodeExporter]

Original comment by dasge...@gmail.com on 1 Jul 2009 at 8:37

• Changed state: Fixed