How can you tell if an outsider is using your wireless network?

Answer:
You should log in as administrator/root in your router. Then need to check DHCP client list (can be called different names depending on model and manufacture). You will see MAC addresses all computers connected to your router. Find out which ones are yours, everything else if any any is intruder(s).
First answer by Archangel dmitry. Last edit by Archangel dmitry. Contributor trust: 473 [recommend contributor recommended]. Question popularity: 1 [recommend question].