As always, the first versions of any software suffer from various bugs, some more flagrant than others but ultimately ... failures. OS X Yosemite has not been the exception in this regard and is that several users have discovered a variety of connectivity problems in wireless networks.
These problems range from dropped connections as well as the inability to "go online" even though the computer is connected to the router via Wi-Fi and this if it has access outside as well as strangely low connection speeds. These problems among others seem to occur in a higher percentage in those Macs that have upgraded to Yosemite from OS X Mavericks instead of those that already come standard a "clean" copy of OS X Yosemite, so we can come to think that it may be a problem of incorrect network configuration that is carried over from the previous system, so the solution may lie in correctly configuring the software.
From this point on we will give a general solution to specific problems with which it is possible that some user has a very particular casuistry that does not correspond to this solution, however, it is most likely that most can be solved as long as they are about software related topics. This will involve editing some configuration files, so it is highly recommended to make a backup copy with Time Machine.
Remove network preferences
On some occasions, although it seems a drastic way to proceed, andl delete all .plist files that save the network configurations of the equipment, solve a large part of problems that may have been dragged from a system update. The steps to follow will be to deactivate the Wi-Fi connection, then from the Finder with CMD + Shift + G we will enter the following path:
/Library/Preferences/SystemConfiguration/
Inside this folder we will select the .plist files and we will move them to a folder on the desktop as a backup (for what could happen) although if we have the copy in Time Machine there would be no problems.
- com.apple.airport.preferences.plist
- com.apple.network.identification.plist
- com.apple.wifi.message-tracer.plist
- NetworkInterfaces. plist
- preferences. plist
We will return to activate Wi-Fi connection in the wireless menu again. This will force OS X to create all the network configuration files. This may by itself solve the problems, although it is likely that we still have to adjust some customization options in the connection.