MAC Address


Senior Member
Simple question

How do I detemine the MAC address for my laptops etc. I need to enter them into my router and limit usage to those computers.

Someone has been stealing my bandwith.

The mac address of all connected devices should be listed in the wireless "section" of you router.
I need to add those in to the router they are not there now. So I was looking on the individual laptops. I want to limit the router to handling only those MAC address's I put in there.

I had hope dmy router would display a list but it doesnt. Its the standard Linksys Wireless G router.

Ok I just got it to list the MAC address's. Would help if I re-enable the wireless. Had it off all day to see if that was waht was clogging my router.
The ipconfig /all command will tell you the mac address (look for the physical address value). Keep in mind that it's pretty easy to spoof MAC addresses, so if someone is really interested in your connectivity, this won't stop them at all.
I already found someone using my router and put them on the list to deny access. My outoging emails were being filtered by the cable provider since there looked like spaming was going on. I did virus scans etc and everything was normal.

I disabled the wireless and everything was fine all day. So now I found someone on my router and have them locked out and it seems to be ok.

I will give it a few days and if necessary enable security but I would rather not since my work laptop is hard to make changes to.
If I do that I cant use my work Laptop unless I can convince my employer to make teh changes. You need admin rights to do everything with the work laptop so I am trying to work around it.

I already have a problem with the filter shutting down again. But I dont see anyone else on the router at the moment.
Assuming your router allows you, I would do the following steps:
  • Create 'reservations' for your systems, so they always have the same IP.
  • Create rules for those IP addresses to allow internet access.
  • Block all outgoing traffic for all IP addresses (should be the last rule).
This would allow you to get online, but anyone else should be blocked. You could even go farther, and disable the laptop rule whenever you aren't home (in case the person tries to find useable IP addresses).
We have 5 laptops/tablets. I cant see anyone else on now and yet the filter shutdown once I enabled the wireless. Yet I had the one wireless laptop that is online now of all night last night and the filter kicked in after about 10 hours. Yet I had it on for 30 mins and the filter kicked in.

Might just be a coincidence. I need to play with this some more once everyone is in bed (my son is on his desktop).

Maybe I should just pull the plug for a week and let people find another router to hijack.
Ok just in the off chance its my wifes laptop is there a way I can monitor the outoging activity? I want to see if its got a virus I cant detect and is sending out spam somehow. That may be the problem but I am not sure.

I do see in the connection activity that there is constant outgoing packets but I am not sure if that is emails gogin out or normal traffic even though the browsers are all closed.
maybe it is not a problem with someone else... you seem focased on the wireless. is the desktop "clean"

As far as I can tell teh desktops are ok. When I shut down the wireless it was fine. I used that as the process of elimination step 1.

I then found someone using my router and blocked them. At first I thought that was it. But I am still having a problem so I am looking deeper.

I just shutdown all of the computers except the laptop I just fired up tonight to see if this is the problem. If not I will try one computer at a time until I find if it is on my network.


Less than 30 mins and the filter kicked in and no email with just the wireless laptop on so its not the desktops. It could still be someone elses laptop or the modem itself.
Depending on the router, you can look at the log on the router itself. There are also software packages to recieve that information via SNMP and display it or slice/dice on a PC (like WallWatcher was an old linksys one).

You can look at the connections and which IP address they are from, then look further based on that. You can then start paying attention to tasks that are running,etc.

Note it may not be a virus, so it might not be being picked up if it is something to spam or send back information. May want to run one of the free spyware detectors as well.

I ran spyware programs as well when I did the virus scans. Wireless was off all night and the mail works fine this morning. I will leave it off all day and try tonight.

Since my wifes laptop was off yesterday and the wireless was enabled adn I had the problem yesterday morning it might not be her laptop. Nothing else was on in my house that was wireless yesterday yet I had a problem when I put the wireless back on and turned on her laptop last night.

I dont see anyone else on the router wirelessly except the one I blocked.

I just enabled the log and noted that about once a minute or two I see something going out to a "POP3". the rest of the log is WWW such as me acessing cocoontech like I am now.
Hmm, and the filter that kicks in, that is from Cablevision? How can you tell it kicks in (I've never seen that)? Just looking for clues.

I am also wondering if it needs to be one of your computers that is the culprit (if someone was able to get a connection, they could bulk load spam, but I'm not sure if that would trigger your 'filter').


If it is one of your computers, then if you leave them all on, and disable the wireless you would still see an issue right (assuming they have wired connections)? Might want to test that.