someone have hacked my WLAN and i want to ban him !

if he is connected to the network who can i know his MAC address

If you can ping his IP within your network, you can find the mac address in the arp table from this command (assuming you run Windows)

which one ?

http://s17.postimage.org/xxmztyryl/sdsdsd.png

I'd suggest that you can try pinging around your subnet (192.168.1.#) to check for possible unknowns. (I mean, the hacker might be on 192.168.1.4, or 6, or 7, etc ... you know?). But you need to be certain that the hacker is connected to your WLAN when you are trying this.

Now, if you are sure that screenshot is showing all the addresses on your network, I would personally narrow it down to the 2nd or 3rd one (192.168.1.3 or 192.168.1.5). Again, this is assuming one of those is the hacker's address.

It is up to you to figure out which one belongs to the intruder.

Also, it should be safe to ignore the IP addresses that don't start with 192. You should also ignore the 192.168.1.255 -- that one is standard.

your router will tell you any and all mac addresses currently connected to the wlan in the station info screen

the DHCP screen will also list mac addresses bound to host device names.

VBA-M

and one more thing who do i know the IP address of an AP ( not mine ) that is i cant connect to and port ?