Q: 5GHz 802.11ac Network
By default, does an AirPort Extreme or an AirPort Time Capsule provide both 2.4GHz and 5GHz connections? Or does it take some steps to set up a 5GHz network? Is it done by choosing "wireless options" in AirPort Utility and ticking the box opposite "5GHz network name"? Thank you.
MacBook Pro with Retina display, OS X El Capitan (10.11.1)
Posted on Nov 12, 2015 10:25 PM
But after clicking the 5GHz box and naming a 5GHz network in "wireless options", does it mean that there are no longer any 2.4GHz signals? My ageing mother uses a couple of older devices which are not 802.11ac. Will her older devices, which might be 802.11g or 802.11n, still be able to connect to the updated WiFi network here?
The TC and Extreme will still create a 2.4 GHz network with the name specified in the Wireless Network Name field. So you are setting up two networks at once (three actually if you set up a Guest network too) and both have to be connected to individually. So your mother might connect to the 2.4 GHz network for her computing and it be used for devices like HP printers which at last check were all 2.4 GHz (though that can be overcome with a USB cable connection to a 5 GHz device). Obviously the switching between the two can become a pain it both 2.4 GHz and 5 GHz are used routinely with different devices and each network. And the devices need to be on the save network to communicate with each other, which is why I leave my network on automatic. But I do have less noise and don't get the diagnostic advice you get.
You might be able to find a "quieter" 2.4 GHz channel by listening for an extended period and studying the logs. Apple's tool is explained here but other tools are more convenient to read to me. I've used WiFi Scanner most recently but there are lots of similar tools to choose from. You can then manually select a channel for 2.4 GHz under the TC or Extreme Wireless > Wireless Options in AirPort Utility for the quietest channel over time, and let the TC and Extreme switch to 5 GHz on one network when it thinks best without creating a separate 5 GHz network outright.
Should DNS Servers be entered in "Network" in "System Preferences" instead of both or either of the AirPort Time Capsule and AirPort Extreme which make up my network?
DNS Servers should be changed on the Modem whenever possible. If you change it there you don't need to worry about a change on TC or Extreme. And if you can't change on modem (some ISP prevent this) you can change on the primary wifi device (the one creating the network) if you have the other device set to extend network. This is also true if you have the devices connected by ethernet to create a Roaming Network. Primary device connected to WAN as close as you can get to the WAN is best place to change DNS. I know of no reason to set DNS independently on each device though I sure there are cases when people find it useful.
Posted on Nov 13, 2015 9:07 PM