How to check if an IP is currently connected to a server?

Check users connected to wireless network?

• I have a linksys Wireless-g WRT54G router...I want to check all of the users who are connected to my router. I think a neighbor is leaching it and I want to get his MAC address but he isn't using my DHCP auto ip thing. He set up his computer like you would for a server with a static ip and I don't know how I would go about finding it. How do you check all of the users connected? not just the DHCP users?

• Answer:

  Most linksys wireless router store all the MAC addresses of the wifi network cards with which it communicates, I would assume that yours does the same: if you don't see his MAC address there your neighbor is probably not using your network. If you are still suspicious, there is an option in the linksys operating system of my wireless router to log all the network connections and to send this log to a PC: I never used it, but I am quite sure it would tell you about all connections, even those with an IP address fixed manually as you suggested. Finally, if you don't want other users to "piggy-back" on your network, rather than go and yell at them when they do so, it is simpler to protect the access to your router through a "WEP key". This will ask any person that wishes to connect to your router to enter a password, and will refuse access to people who don't know it.