wifi

tl;dr You can get Gigabit networking working on any current Raspberry Pi (A+, B+, Pi 2 model B, Pi 3 model B), and you can increase the throughput to at least 300+ Mbps (up from the standard 100 Mbps connection via built-in Ethernet).

Note about model 3 B+: The Raspberry Pi 3 model B+ includes a Gigabit wired LAN adapter onboard—though it's still hampered by the USB 2.0 bus speed (so in real world use you get ~224 Mbps instead of ~950 Mbps). So if you have a 3 B+, there's no need to buy an external USB Gigabit adapter if you want to max out the wired networking speed!

Note: On Raspberry Pi models with built-in WiFi (e.g. the Raspberry Pi 3 model B), USB WiFi interfaces will use wlan1 (wlan0 is reserved for the first interface, in this case the internal one).

Since this is maybe the fourth time I've done this process on my Raspberry Pis, I decided to document the process of setting up cheap mini WiFi adapters on a Raspberry Pi A+/B+/2.

This process works great with any USB WiFi adapter that's supported out of the box. My three favorites (due to their inexpensive price and decent connection speed/reliability) are:

Update (3/4/14): Mac OS X 10.9.2 seems to fix at least the latency issue—and possibly dropped connections as well, at least for most users I've spoken with... We'll see!

Update 2 (11/25/14): If you're having trouble with iOS 8 and/or Yosemite, it could be related to AirDrop services over WiFi. Please see WiFried: iOS 8 WiFi Issue

For the past few months, I've been battling my 2013 11" MacBook Air's WiFi problems. I've taken the MacBook to the Genius Bar twice, and have attempted dozens of fixes. Judging by the number of individuals who have posted to this thread on Apple's Support Communities forum, among many other similar threads, I'm not the only MacBook Air owner suffering from WiFi issues like high latency, slow throughput, connection dropouts, and other random problems.

Here are some of the symptoms I and others have encountered:

I was migrating all the data from a friend's old MacBook (which was running Mac OS X Tiger) to her new MacBook Air (running Mac OS X Mountain Lion), and besides a WiFi hiccup, everything went smoothly (I had to clone the old MacBook's drive to a USB disk, then use Setup Assistant to migrate the data from that disk to the new MacBook Air).

During the Setup Assistant, I could easily connect to my WiFi network, but after the migration was complete, I couldn't connect anymore. I kept getting a pesky error: "Could not join [network]. A connection timeout has occurred." (see picture of error dialog here). Looking through Apple's forums and elsewhere was not much help, because this message seems to be a very generic 'something weird happened' error, happening in many different circumstances.

However, knowing that the keychain and old WiFi connection data from the old Mac had transferred over to the new Mac, and knowing that something might've gone screwy with the network information, I decided to do the following:

I spent the greater part of this afternoon trying to get my AirPort Express to connect to the Internet and share an IP address using a Motorola SB5101 Cable modem (with Charter Internet)... and since the solution was so simple and annoyingly stupid, I thought I'd post it here, for my reference and for anyone else spending an afternoon thinking his AirPort Express is dead.

As it turns out, the cable modem (this one, and likely many others) will only remember the MAC address of the first device it recognized when you last power cycled the modem.

When the Internet went down at my condo yesterday, I turned off my cable modem, plugged my Mac straight into it, turned the modem on, and use the internet via this direct connection for a while. When I plugged the AirPort Express back into the SB5101, I just got a flashing yellow (amber) light, and in the Airport Utility, a notice that the 'Internet Connection wasn't working'.