Wifi box produces three SSIDs?

Question

While using a friend's wifi, he said I should use his SSID, let's call it XYZ's Wifi. When I started my Macbook Pro, three SSIDs came up. Two were called XYZ's Wifi and the third was called XYZ's Guest Wifi. One of the ones called XYZ's Wifi disappeared within 1-2 seconds and did not reappear. But the "guest" wifi did persist and I was told not to use it.

Are there actually Wifi boxes out there that support two simultaneous SSIDs?

I advised him that maybe a neighbor is using a router with the same/similar name to trick him, and capturing packets.

How can I tell whether they are actually both in the same router, or different routers?

On the Mac it seems we don't have an iwconfig command, so I don't know how I can print out the MACs of these router(s).

Thanks.

Answer 1

Are there actually Wifi boxes out there that support two simultaneous SSIDs?

Yes, this is also a major feature in more advanced wireless systems.

Two were called XYZ's Wifi and the third was called XYZ's Guest Wifi. One of the ones called XYZ's Wifi disappeared within 1-2 seconds and did not reappear.

That probably relates to the mechanism by which this usually happens. Each broadcast of an SSID uses a different MAC address. It's possible that two addresses were spun up with the same name, then one of them changed to have the guest name.

Having these different identities allows for different settings including varied speed, security, and other settings though security is often the focus in being able to permit an open network and an authenticated network in parallel.

How can I tell whether they are actually both in the same router, or different routers?

Ultimately, checking the router configuration is the appropriate answer to that question.

Answer 2

A quick way of figuring if the SSIDs are coming from the same router is unplugging the router and seeing if they go out at the same time. The same should happen when plugin the router back in.