unknown computers connected to network

  eddiejackr 11:19 15 Mar 2006

Have just set up a "secure" wireless network, but keep getting message that unknown computers are connected to this. When I go to properties for these, one shows up as a router - is it my router or someone elses - how can I tell? The other has nothing that makes any sense to me shown in it's properties. There are MAC addresses, but these mean nothing to me. Please help....
P.S. I live in the middle of nowhere so it seems unlikely that anyone else is connected. Nearest neighbour is 0.25 mile away...

  Danoh 11:32 15 Mar 2006

This is best posted in the Networking forum, but no matter;
We'll need more information (e.g brand and model of Router, how your PCs are connected to the router, all wirelessly or mixed wired and wireless, which security measure had you set ~ e.g. what SSID, MAC address filtering on, WEP or WPA, "Ping" response disabled, etc.).

You say you have setup your wireless network.
While connected via an Ethernet cable to your router and accessing its configuration page, using a browser (such as Internet Explorer and entering an IP address such as or;

Did you change the default SSID to a name of your own choosing so you know its definitely your router your wireless Pcs are connecting to?

Did you add each MAC address for each of your PC's wireless components to the MAC Address filtering section? (You get your PCs' MAC addresses by Start> Run> cmd> "Ipconfig /all" without the quotes, and noting down the "physical address" which is the MAC address.


If its a second hand router, the settings you see are probably left over from the previous owner. You need to do some housekeeping and remove those which do not relate to your equipment.
Also to change the Router's configuration page's login password, the SSID name, WEP/WPA keyword/password.

Hope that is a good start for you.

  Danoh 13:02 15 Mar 2006

Just came across your other thread which adds more information; click here

  Danoh 13:07 15 Mar 2006

Hopefully some of my points/Qs above will ring a bell w.r.t. advice and guidance provided by Linksys support.

Is your problem an inability to connect your laptop wirelessly for internet access?

This thread of yours is about something else, which might be connected to your problem.
Can you tell us the exact messages you get and the steps you took leading up to the messages being displayed?

  eddiejackr 21:55 15 Mar 2006

The router is Linksys WAG354G; one PC connected via ethernet cable; one laptop connected via Linksys adaptor WPC54G.Yes, I changed the SSID to a name of my own; WEP was set up when I was talking to Linksys helpline so the laptop uses a key to connect to the network and the network is listed as secure. I don't know about MAC address filtering and Ping..I didn't do anything to do with MAC addresses and I don't recall this from the procedures I went thro on the helpline.

It is not a second hand router.

Laptop connects to the wireless network but not to the internet. It did work fine at first - just not after the laptop was switched off and on again later - so I feel that the internet problem must be something quite straightforward?

I entered two seperate threads as I assumed they were not related...

I've just switched laptop on - it connects to network fine with a good signal strength.Then I go to Internet explorer - click here (for no particular reason - just to test the connection) - progress bar at foot of page is very very slow. Then "Internet Explorer could not open the search page". Tried other address and get usual "the page cannot be displayed"

If i try to retrieve mail in Outlook 97 I get "a connection to the remote computer could not be established because the modem was not found or was busy" (and yet the network connection is still live..)

If I go to PCcillin Internet Security 14 and try to connect for an update I get message "an error occurred while connecting to the internet. Please check your proxy settings and/or personal firewall exception list to enable the generic host process for Win32 Services(56)."

I know pc cillin firewall is off - i think they told me to do that on the helpline. I know pccillin is listed as an acceptable site in the exception list anyway.

Grateful for more help. Thanks for your time.

  Danoh 22:43 15 Mar 2006

Hacking WEP is proven and known to certain parties, so best to move to WPA a.s.a.p.

If you have not entered MAC addresses and its a new router, then this sounds serious.
First, you need to find out what your kits MAC addresses are;
On your PC and then your laptop, click on Start> Run> and type "cmd" without the quotation marks.
Then type "ipconfig /all" again leaving the quotes out.
Amongst the items which will now be listed is a "physical address".
This is the MAC address of your laptop's/PC's wireless or ethernet component; make a note of it for later.

Login to your router's config page via your PC which is connected via an Ethernet cable.
If you have not set a password to Login to your router's config page, DO set one up, A.S.A.P.!

Change your SSID to something which is obscure, as long as possible, and includes alphabet, numbers as well as special characters (e.g. _ > ^ etc)
It is advisable to disable the broadcast of your SSID. So look for an option which disables the broadcast of your SSID

Change to WPA and use a password which is also as long as possible and which includes special characters, etc.
If you have a WPA2-PSK encryption option, go for that one in preference to WPA-PSK.

Look for an option called MAC Address;
Delete all the MAC addresses you have found already.
Add only the MAC addresses you have noted down for your own equipment.

Look for some option called "WAN" or "ICMP" Ping Blocking and turn it on. Especially if your SSID is no longer broadcast, if your router does not automatically respond to a Ping from an external wireless probe, it makes it harder to spot your router's transmission.

>> Take careful and accurate notes of your router settings above <<

On your laptop, delete and then add a new Preferred Wireless Network;

Start> Control Panel> Network Connections>
Right mouse click on Wireless Connections and click on Properties.
Click on the middle tab.
Delete/"Remove" any entry in the Preferred Network box.
Click "Add" to create an new Preferred Network entry, carefully re-entering the settings used for your Router above.

Before you log-off your laptop, it should automatically connect to your router if its within wireless range.

The internet access aspect is less critical then securing your wireless network first.

  woodchip 22:49 15 Mar 2006

Have you tried turning the Router off then back on?

  namtas 23:28 15 Mar 2006

If it is any consolation I had exactly this problem when setting up a network with the Linksys BEFW11S4 router. I contacted Linksys to ask if I was being hacked they replied no but never gave explanation and it just dissapeared.

  eddiejackr 15:03 16 Mar 2006

Have done what I can of this, but please see the following questions.
In router confi site I am not given option of WPA or WPA-PSK. It only offers -Disable -Pre-shared key or -WEP )64 or 128 bit encryption). I did find another section on Wireless Access with two options -allow all or -restrict access. I didn't change these so it's still set to WEP.

Can't find ant ref antwhere to MAC addresses so couldn't follow your instrux on this...

Can't find WAN or ICMP Ping blocking either....

On the laptop I have the option of Network Authentication to be -open -shared -WPA or -WPA-PSK (TKIP or AES. AT the moment it is set for open and WEP.

Now i do have a network connection AND my laptop is accessing the internet!! WOW!

BUT! Despite the fact that the laptop is connected to the internet, when I look in view available networks and refresh this - it says no wireless networks were found in range - previously my network SSID name appeared here.

ALSO - i still get the message about unklnown computers connected - one has the MAC address that I found on the laptop as you instructed, but the other is the same as before, but not the laptop or pc MACs.

What next? Thanks again!

  eddiejackr 19:58 16 Mar 2006

Lost the network connection (computer still in same place - only 2 metres from router!) and lost the internet connex but fiddled about and it's back - I don't think my fiddling did this - it just seems very erratic -so I'm not convinced that it won't be lost again when I switch off tonight and on again tomorrow,,,

Re MAC addresses - when message about unknown computers comes on laptop it shows the PC MAC address so I have accepted these as trusted on laptop and PC respectively. There is still another address, but I see that the IP address is the one I was using to connect to Linksys when I configured the router - so does that mean it's ok? It says it's a router.....should I set it as trusted?

  eddiejackr 11:40 19 Mar 2006


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