Strange AirPort Extreme Guest Network BSSID

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Strange AirPort Extreme Guest Network BSSID

This is the first time I have used the Guest Network feature on my AirPort Extreme without a password.

I have two children at home with their Chromebooks and they wouldn't stay connected to our WiFi network that uses a password. When their Chromebooks go to sleep they "forget" our home WiFi password.

I get strange BSSID and IP address on their laptops when they connect to the Guest WiFi network.

The IP address is not on my normal network and none of the Apple wireless routers I own have the BSSID that appears on their Chromebooks:

172.16.42.1 Gateway/DNS

172.16.42.3 assigned to the device

Is this normal for a Guest Network created on Apple AirPort Extreme? If so how do I setup what DNS address they use. I use OpenDNS to filter the web for them.

Posted on Apr 8, 2020 11:36 AM

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Answer 1

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Bob Timmons

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Apr 8, 2020 11:57 AM in response to johnnyjackhammer

The devices are definitely using 172.16.42.1 as the "automatic name server" for the device instead of the main network's DNS

No, you are confused about how the AirPort displays things. 172.16.42.1 is getting the same DNS information as your "main" network 10.0.1.1.

For example, I am using the DNS Server numbers 8.8.8.8 and 8.8.8.4 on my AirPort Extreme. Devices on the guest network show a DNS reading of 172.16.42.1 as their "server" but this is simply saying that they are getting their DNS info from the AirPort Extreme......which is using 8.8.8.8, etc.

Apple provides very little information or documentation to tell you things like this though.

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Answer 2

Apr 8, 2020 11:47 AM in response to johnnyjackhammer

Perfectly normal.

172.16.42.1 is the factory default setting for the Guest Network / AirPort router., so it would be logical that any devices that are connected to the Guest Network would receive IP addresses like 172.16.42.2, 172.16.42.3, etc.

Devices on the Guest Network use the same DNS information that devices on the "main" network on the AirPort Extreme use. Apple does not provide you with the option to do otherwise from the AirPort Extreme or AirPort Utility.

If you have not changed any of the settings for the AirPort Extreme "main" network, devices on that network are receiving IP addresses that look like 10.0.1.2, 10.0.1.3, etc. The AirPort Extreme assigns itself 10.0.1.1.

As far as having no password required for the Guest Network, that would mean that anyone in range of your AirPort Extreme will be able to connect to the Guest Network and gain Internet access in addition to being able to "see" other devices on the Guest Network.

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Answer 3

Apr 8, 2020 11:51 AM in response to Bob Timmons

@Bob Timmons.

Thanks. That makes sense,,, since the idea is to keep guests off your main network. But the DNS situation is odd.

The devices are definitely using 172.16.42.1 as the "automatic name server" for the device instead of the main network's DNS. None of the blocks I have set up are working so I know that 172.16.42.1 is not forwarding to the main network's DNS address.

I can change this on their device by using "custom name servers" but I am not sure how well those stick over restarts.

The other odd thing is the new BSSID. It's not listed on the AirPort Extreme on in it's details when Command-Option double clicking on it in AirPort Utility.

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Answer 4

Apr 8, 2020 12:30 PM in response to Bob Timmons

@Bob Timmons.

Just looked and there is an 'airport' command for Terminal access. This ancient MacWorld article explains how to find it and setup an alias for it. Although there is nothing there dealing with the guest network as far as I can tell.

EDIT: You are correct. My DNS filters are working. Coincidently I recently removed the one filter that I used to check the premise that the guest network was sending DNS queries through the main networks DNS resolvers.

Still, you would think the BSSID of the guest network would be visible somewhere in AirPort Utiltiy so people don't freak! I can't find that anywhere.

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Answer 5

Apr 8, 2020 3:28 PM in response to johnnyjackhammer

If it's there in AirPort Utility, I can't find it, even after trying some tricks like holding down the option key while you click on a tab or setting.

About the closest that you will come is checking the Network tab, then click on Network Options to see that devices are assigned IPv4 addresses from 10.0.1.2 to 10.0.1.200 on the Main Network and 172.16.42.2 to 172.16.42.200 on the Guest Network. You can change these around a bit.......so the Main Network could be assigned 10.0.5.2 to 10.0.5.200, etc. No real settings to control IPv6 address assignments.

Then, you just have to know that Apple always assigns the AirPort Extreme device the .1 address on the Main Network and .1 on the Guest Network.

The Guest Network feature on the AirPorts works via a simple VLAN, but again Apple does not divulge details to us common folk.

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Strange AirPort Extreme Guest Network BSSID

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