how can my neighbour know that,if I'm stealing his wireless Internet?

Answer 1

He may notice a fall in speed if you do anything heavy. Also his router will keep alog of your access, and a record of your machine's mac address. This will remain listed long after you cease using his connection. If he reports this you can be traced by this information and can serve up to five years in prison for it.

Answer 2

There are many ways to know someone is connecting. If you neighbor has some of the newer antivirus/antispy ware packages, (Like Trend Micros Internet Suite) it tells you every time a computer connection occurs, you can also click the button to show all computers and IP's that are part of the network. There are many free programs that will do this also.

He can also check the logs on his router, if they are enabled, those too will show all computers that have connected. The data available includes the time, ip address used, MAC address of the connect computer.

Don't forget that when you connect to a WIFI router, you join the LOCAL network so using any of the windows networking system you can SEE any machine on the system. If you know how, you can connect into any of those machines!

There are now a lot of ID thieves using these techniques (even at Public Wifi locations) and packet recorders which they use to trap all traffic and they are just hoping you will connect and go to your bank or use your email. It really isn't a good idea to connect to your neighbor unless you have his/her permission and know exactly what you are connecting into!

Answer 3

Easy. If your neighbor hasn't enabled his/her WEP or Security on his router you are able to share his/her internet connection.

If you are both using the internet at the same time he/she won't notice you right away unless he/she logs on his/her router. Once your neighbor is logged-on to his router, there is higher chance he will see you and other people using his internet connection.
He/she will notice you and the others with your 'Computer's Name.' and the IP Address of your computer. However he/she won't be able to know directly who is who exactly is using his/her internet connection. If he/she does somehow see someone using his/her internet connection, it is very likely he will enable his/her router's WEP encryption or Security. WEP is some sort security for the router that enable to user to enter a password in order to secure his internet connection.

Answer 4

It is fairly easy for him to tell if he knows what to look for - for example data lights on his router/modem will likely flash when he isn't using the Internet. Also many wireless routers have an option like "Attached devices", which will show what computers are currently accessing them.