Please help me! Unknown Mac Address

[igkillabeeiv]

Hi everyone, so this is new, I've never had anything like this happen before this point in time. So I have xfinity, their triple play deal with a DPC3941T modem/router. Just tonight I logged in as I do randomly from time to time just to check in on stuff & noticed this. Aside from the other normal devices, along with my Note 8 displaying the correct Mac address showing as connected BUT it also had on not connected but was previously connected is my Note 8 but this had a -6 at the end of it with a Mac address that when searched for comes back with nothing...? Any ideas?? This is not good, correct?? I'm not a complete idiot with all this kind of stuff, but no professional, guess above average knowledgeable... But I have no clue with this. Any help would be greatly appreciated

 

[kanewolf]

Usually a device with an almost identical (last digit different) MAC address is because of 2.4Ghz and 5Ghz connection. Each radio has to have a unique MAC address, distinguished by consecutive MAC addresses.

 

[The Paladin]

did you check the MAC address type with this site, when I have "unknown mac address on my network" I seek what "kind" of device ie manufacturer to give me a hint.

https/aruljohn.com/mac.pl

 

[igkillabeeiv]

SEE IMAGE HERE

Yes I have checked it there & the mac address is totally different... I'm editing the screenshot now to take out the personal info & will upload it as soon as I'm done

 

[kanewolf]

All those devices have been in range of your router, but notice, that unlike your Note 8 they don't have an IP address. They attempted to connect to your device and failed. It is not uncommon to see devices listed like this. I don't think you have anything to worry about.
If you are concerned, then there are four things to check/modify on your router.

■ Disable WPS
■ Change admin password to unique strong password
■ Use WPA2 with a unique strong password
■ Disable guest WIFI

I know Xfinity likes to provide "free" hotspots to other subscribers here is how to disable that -- https/www.xfinity.com/support/articles/disable-xfinity-wifi-home-hotspot

 

[igkillabeeiv]

Oh no they all have up addresses I just didnt click them to get the drop down menu... But the thing that concerns me is the galaxy note 8 and on the bottom the galaxy note 8-6 theres only 1 note 8 connecting to my network which is my phone BUT it clearly has 2 separate mac addresses & ip addresses..

]New Image to check out

 

[kanewolf]

Oh no they all have up addresses I just didnt click them to get the drop down menu... But the thing that concerns me is the galaxy note 8 and on the bottom the galaxy note 8-6 theres only 1 note 8 connecting to my network which is my phone BUT it clearly has 2 separate mac addresses & ip addresses..

]New Image to check out

As I said, if you have 2.4 and 5Ghz WIFI you can have two entries with different MAC addresses for the same device.

 

[kanewolf]

An "offline" device is not currently connected but has been in the past. That could be consistent with a 2.4 vs 5Ghz difference. But it could be the Xfiniity "public" connectivity. I don't have Xfinity so I don't know for sure. I posted a link on how to disable that public connectivity.