Hugo’s blog

I had been complaining for the past few months that my wireless card did not work right on my MacBook Pro. The simptoms were the following:

• At home, my Mac would not detect automatically my network, even though it was in the preferred networks list. I always had to pick it by hand.
• Regularly, it would not connect to certain networks, giving me an error. Clicking on Try again would sometimes work, and sometimes my only solution was a reboot.
• I would get poor performance. Pinging a maching would get me sub-second delays with a very regular pattern:
  

  PING xxx (x.x.x.x): 56 data bytes
  64 bytes from x.x.x.x: icmp_seq=0 ttl=58 time=3.927 ms
  64 bytes from x.x.x.x: icmp_seq=1 ttl=58 time=1805.443 ms
  64 bytes from x.x.x.x: icmp_seq=2 ttl=58 time=805.355 ms
  64 bytes from x.x.x.x: icmp_seq=3 ttl=58 time=4.002 ms
  64 bytes from x.x.x.x: icmp_seq=4 ttl=58 time=4.861 ms
  64 bytes from x.x.x.x: icmp_seq=5 ttl=58 time=3.775 ms
  64 bytes from x.x.x.x: icmp_seq=6 ttl=58 time=2000.225 ms
  64 bytes from x.x.x.x: icmp_seq=7 ttl=58 time=1000.141 ms
  64 bytes from x.x.x.x: icmp_seq=8 ttl=58 time=4.067 ms
  64 bytes from x.x.x.x: icmp_seq=9 ttl=58 time=1805.541 ms
  64 bytes from x.x.x.x: icmp_seq=10 ttl=58 time=808.282 ms
  64 bytes from x.x.x.x: icmp_seq=11 ttl=58 time=45.774 ms
  64 bytes from x.x.x.x: icmp_seq=12 ttl=58 time=3.702 ms
  64 bytes from x.x.x.x: icmp_seq=13 ttl=58 time=3.924 ms
  64 bytes from x.x.x.x: icmp_seq=14 ttl=58 time=1998.669 ms
  64 bytes from x.x.x.x: icmp_seq=15 ttl=58 time=998.551 ms
  64 bytes from x.x.x.x: icmp_seq=16 ttl=58 time=3.601 ms
  ^C
  --- xxx ping statistics ---
  17 packets transmitted, 17 packets received, 0% packet loss
  round-trip min/avg/max/stddev = 3.601/664.696/2000.225/778.601 ms
  

• I would occasionally get disconnected from networks.

IT looked at my Mac, ran hardware tests, and did not find the issue. I looked online, and did not find anything obvious, until I finally stumbled upon this lengthy article giving tips for any wireless issue that you might encounter on a Mac.

Near the end of the list (after many other things I tried), there is: Check for/quit third-party wireless applications (monitors/sniffers). And this was my problem: a simple widget showing wireless information, and nothing more. Not only that, but I installed this so long ago, and considered it so innocuous, that it took my a while to even realize that I had something in this category.

I’m amazed that polling the network interface would have such consequences, but it obviously does. Needless to say, I’m much happier about my Mac now, though I have noticed that Intel-based laptops are far less stable than PowerPC-ones: my PowerBook would never crash, while the MacBook Pro does occasionally. Unless it’s another harmless piece of software messing up the system…