I've set up WPA encryption on my WiFi network with a passphrase. This passphrase is visible in plain text when I connect to my router at http://192.168.1.1. But if someone doesn't know this passphrase, he shouldn't be able to get onto my network in the first place, to be able to go to 192.168.1.1, right? I haven't changed the default username and password for my router, and this can be easily looked up online based on manufacturer. So I guess my question is, if someone doesn't have the passphrase, can he even get to the router admin page at 192.168.1.1. Or is there another way he can gain access to my network?
The reason I ask is, I am currently getting messages like "another machine is using the IP address 192.168.1.2, please try again later".