Unknown Ip address accessing my wireless

So there's this unknown ip address with a mac address thats been accessing my wireless...what does that mean?

 

Could be someone leeching your wireless signal or could be an Xbox or some other device you didn't consider. Do you have WPA2 enabled and SSID broadcast disabled or is the network wide open?

 

Ditto gosh1976

Easiest way to find if it's one of your own devices is to turn off the SSID broadcast and change your password. Don't use WEP as your encryption type, even i can hack that.

Either an annoying neighbor will go away or your cell phone, e-reader, kid's DS, game boy, ipod, bluray or some other device will stop going online. Well, they are all going to stop going online until you update the password in each device.

 

By the way when I mean unknown my router couldn't determine the Ip Address at all but it knew the mac address