How do I turn on band steering

The default is band steering ON, which is one SSID, so you want band steering to be OFF.

You can to separate the bands OR enable the Guest Wifi Network which is 2.4GHz only and point your guest to that.

To go with the first solution, go to http://192.168.1.254/cgi-bin/wconfig.ha , enter the Access Code which is on the gateway's label and in the 5GHz section change the Network Name (SSID) to something else.  I usually suggest just adding a -5 onto the end of the current name.  Scroll down and hit Save.  Oh, ignore the dire warnings about the end of civilization if you change the name.

After this, any devices that work better on 5GHz will need to be told to connect to the new SSID you just made but the exiting 2.4 devices should just keep working. 

If you'd rather go the Guest Wifi route, go to http://192.168.1.254/cgi-bin/wconfig_unified.ha and Enable the Guest SSID and again, don't forget to click Save.   Give that Guest Network Name and password to your guest.

Let's disable band steering, @jbTennessee! 

Thanks, @tonydi for explaining how to do this! 

You can also check out our guide on band steering for more instructions. For band steering to work, make sure the two radios on your gateway have the same Wi-Fi network name and password. This is the default setting on your Wi-Fi gateway.

If you changed the network names or passwords, change them back so both radios have matching Wi-Fi info. Here’s how:

1. Sign in to Smart Home Manager. 
2. Select Tools. 
3. Choose Network Notifications. If you have different network names for each radio, you’ll get a Different Network Names notification. To combine your network names, select Choose One and pick the network name you want to keep.

It looks like it was set up correctly in your picture. If you have any other questions, please let us know. Thank you for contacting AT&T Community Forums! 

Raiden, AT&T Community Specialist 

Not sure why you disabled the main 2.4GHz radio and enabled the Guest network.  You want the Guest on 2.4, which you have now with Barlow2, so I don't see a need to kill the main 2.4GHz, that's going to disconnect all of your regular 2.4 devices that can't do 5GHz.

So the way it was initially set up is correct?  I have an old laptop and am trying to set it up on Wi-Fi.  The wifi is not showing up on the laptop although I can see and connect all of the other devices.  

Wow, talk about doing a 180!  You wanted a 2.4 GHz network for a guest, now you are trying to connect an old laptop.

Ok, you have band steering enabled, so one SSID for both main radios (BarlowHonestead).

Since you have the Guest Network enabled (Barlow2) does the laptop see and connect to that SSID.  If not, there's a good chance that the laptop's old wifi chip isn't compatible.  You could try getting a gigabit USB to Wifi adapter, that often solves the problem.

Not a 180, I am trying to connect an old laptop and I read one of the fixes I read up on is turning on band steering.  I was trying to ensure that was done.  It still does not work so I guess the chip isn't compatible.  

Again, the fix that sometimes works is to turn band steering off.  You never actually accomplished that, but the Guest Network test shows you essentially the same thing.  So try an adapter. I've used this cheapie TP-Link in situations like this and it actually works pretty well.