How to block wireless from a particular computer?

[peapody]

Hi guys!

I been googling and searching for an answer for this question...and all of them say to go through the router. But I was just wondering if there is a way to block computers from using my wireless?

Here is the deal...

I have a router set up which uses a WPA password. I live in a apartment building so I gave the password to some of my close friends to use. I monitor who is on my network through just looking at the "shared" section on my finder window. I can tell which computers belong to my friends, but every once in a while, an unknown computer pops up. I believe I have seen 3 unkown computers (PC's) - and they do not use the net frequently.

I would like to block these computers when they come up. Is there a way to do this without going into the router settings and adjusting those protocols?

 

[r.j.s]

Without the router? No.

In the router, in addition to the password, you can set up MAC filtering, both to allow access to your friends' computers and deny access to the others.

 

[CJS7070]

I'm going to have to agree with the router suggestion, depending on your router software you may be able to block or only allow certain MAC addresses on the network. Then, you just get the MAC addresses of the computers you trust (usually through the Wireless NAT settings) and add those into the router.

Good luck!

 

[r.j.s]

Then, you just get the MAC addresses of the computers you trust (usually through the Wireless NAT settings) and add those into the router.

Good luck!

Most routers also keep a log, from which you can pull the MAC addresses as well.

 

[Frosties]

Can you not shut down your own network sharing on YOUR computer. Netsharing or file sharing on os x opens up too much resources. This why you are seeing computers from outside your WAN port if your isp does not restrict some ports or has built a local network in your building. It could also be wireless devices such as ipods and printers of your friends that pops up.

 

[peapody]

Thanks so much guys. I was able to block the unwanted computer by going into my router settings and blocking his mac address. I was so excited I accidentally blocked my own hahah so had to access another computer to reset that aspect but in the end it worked. I was happy to see that I was able to discern which mac addresses were my friends and which were unwanted based on their computer names. Not soo difficult.

Thanks for the help again!

 

[Lanbrown]

If they know what they are doing, they can easily get back online again.

 

[peapody]

If they know what they are doing, they can easily get back online again.

Then what would you suggest?

It seems that they did get back online, and I think it's because they rebooted their system and obtained a new MAC address. I think if I just make life difficult for them by kicking them off a lot, they will get the point to not use my wireless. Any advice?

 

[Lanbrown]

Then what would you suggest?

It seems that they did get back online, and I think it's because they rebooted their system and obtained a new MAC address. I think if I just make life difficult for them by kicking them off a lot, they will get the point to not use my wireless. Any advice?

The MAC is NOT dynamic, but can be changed. You need to do one of several things or what I would do is ALL of them.

1) If you can only allow certain MAC addresses, then do that. Rather than deny certain ones, only allow certain ones. This will make it harder for them, but not impossible.

2) Reduce the transmitting power; this will make your coverage area less. Depending on how far away they are, they may not get very good service anymore.

3) Change the key. Do not tell your "friends" what it is. Some OS's allow you to see what it is, some it is harder. If they are the ones giving it out, they can't if they don't know it.

4) If you are not using WPA2, if your equipment supports it, start using it.

5) Change the SSID and make it hidden.

6) If you can assign an IP to a MAC, then do this as well. Not all gear supports this. While you are still using DHCP, you get the same IP address. Then make the DHCP pool very small, like one address and make the lease time very long. Have a machine connect and get an IP address. This will leave no IP's for them to get.

If they know what they are doing, they can work around most of the above. If you periodically change the Wireless key, it will make it hard for them.

You might be able to find who they are by the machine name they provide to the DHCP portion of your router. They are stealing your connection and is a crime. Find them and file a police report.