MacOS – OS X 10.7.4 Wi-Fi 802.11d network interface country code switching

macoswifi

So I live in Sweden and since a couple of days ago one of my neighbors are broadcasting country code "US" from their AP, rendering my newly awaken MBA 2011 confused, so after a couple of seconds it changes the country code on the wireless interface to "US" and my own network SSID disappears.

Apparently this functionality is according to the specifications of the 802.11d protocol and simplifies manufacturing and country specific regulations for wireless equipment.

This so called "feature" is making my life a real pain for the moment and I'd rather not re-configure my own AP to a channel which is included in both the US and SE/EU array of accepted channels for a number of reasons.

Is there a way to disable this country code switching functionality in OS X 10.7.4?

Best Answer

Not that I am aware of (Believe me I've looked). I had this issue too (See my blog post here: http://jeff-with-a-g.blogspot.com.au/2012/04/5ghz-wifi-on-your-mac-got-you-down.html).

In the end I had to choose a channel that worked in all of the regulatory domains that my neighbours' wireless access points were broadcasting. That may be a bit trickier in Europe given the smaller number of channels available.

This doesn't seem to affect Macs running Snow Leopard so I guess it's an issue with Lion. Maybe Mountain Lion will provide a fix.

Related Solutions

MacOS – Change Mac OS X Wireless Card Country Code

802.11d is the protocol that wireless access points use to broadcast (among other things) the regulatory domain (i.e. country codes) in which it is supposed to be operating. It seems that there may be no clear rule for what to do when various equipment is broadcasting conflicting regulatory domain information.

The ideal solution would be to disable/replace/reconfigure the equipment that is broadcasting the incorrect information.

I found an (oldish) Apple Discussions thread that indicates that indicates that a Mac’s AirPort hardware will use the first country code it hears after powering on or waking from sleep. Later postings in the thread (on the second page) indicate that it is sufficient to just power off/on the AirPort hardware itself and not the whole system. A couple of people reported success using a script to repeatedly turn the AirPort interface off and on (using networksetup) until it happened to acquire the desired state (as reported by system_profiler).

Based on TA25972, it seems that older equipment (presumably models that do not listen for 802.11d information) may not even be able to switch “country codes”.

MacOS – Making a Program Use a Specific Network Interface

Add a static route for your irc server. For example I have 2 interfaces: wired (en0) and WiFi (en1) of which the wired one is the default. So if I get a route to a server, it will go through the default interface (see interface line in output) :

MacMini:~ root# netstat -rn | grep -i default
default            10.0.0.1           UGSc          198       10     en0
default            172.20.10.1        UGScI           0        0     en1

MacMini:~ root# route get tyr.be
   route to: squarespace.com
destination: squarespace.com
    gateway: 10.0.0.1
  interface: en0
      flags: <UP,GATEWAY,HOST,DONE,WASCLONED,IFSCOPE,IFREF>
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
       0         0         0         0         0         0      1500         0

But if I add a static route through the WiFi interface en1 however :

MacMini:~ root# route add 65.39.205.54/32 172.20.10.1
add net 65.39.205.54: gateway 172.20.10.1

MacMini:~ root# netstat -rn | grep -i 65.39.205.54
65.39.205.54/32    172.20.10.1        UGSc            1        0     en1

MacMini:~ root# route get tyr.be
   route to: squarespace.com
destination: squarespace.com
  interface: en1
      flags: <UP,HOST,DONE,LLINFO,STATIC>
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
       0         0         0         0         0         0      1500         0

The route will disappear every time you reboot. To make it permanent you would have to create a script launched as a startup item or a custom launchd script.

Best Answer

Related Solutions

MacOS – Change Mac OS X Wireless Card Country Code

MacOS – Making a Program Use a Specific Network Interface

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