Belkin N750, security problems with ISP

[Nonprofit]

Hi All,

I work from home and I have run into an issue with my new Belkin N750 router. When I use the Belkin (and only when I use the Belkin) 'unknown' (or, as I like to call them, 'rogue') computers show up on my home network.

I do not believe anything malicious is occurring, but I am trying to figure out why this is happening and how to prevent it.

INFO: My ISP is a local cable company (very local, not a regional or national company), I am running windows 7 and Mac OSX, have a Belkin router (NAT), a LAN and wireless.

On both the windows and mac machines I am seeing these 'unknown' computers on the network. In windows, they appear as 'computers' when I go to Network. I see my personal computers, and then I see up to 3 other computers.

None of which are mine, and none of which have names that I have ever used for a computer that I own.

Here is a screenshot: »avatar12.com/network.jpg - in that example, Blacksmith is the 'unknown' computer.

Another computer that occasionally shows up is "grandmascomputer" - this sort of makes me think I am, for whatever reason, seeing someone else's home network.

My wireless: My wireless network is protected using WPA/WPA2-Personal (PSK).

I have changed the SSID and Passwords and have looked at my router's DHCP table and the only computers listed there are my personal computers.

I am as certain as I can be that these 'unknown' computers are not piggybacking on my wireless. (Also, I have no neighbors - I live in the mountains... and there are no other houses around me)

More info: I am unable to access these computers, I am unable to ping them. I am not using a homegroup. I am not, nor have I ever, run hamachi, or any other vpn or network extending software/service.

Any ideas?

As mentioned. The problem does not occur with my old router. Nor does it happen with a new Linksys E1200

 

[stevech]

You're prudently using encryption on WiFi, and no doubt with a non-obvious pass phrase.

And we'll assume that the wired network has no unauthorized connections.

So those phantom computers...
Let's assume your Belkin does not have any open ports from LAN to WAN and vice-versa.

Maybe your small-town ISP's modem in bridging mode is not configured correctly so other PC's shares or media servers go through the modem to the WAN port of your router and then on to your LAN.

In the Belkin, check all the port forwarding settings. Turn off UPnP.

Wild guesses, these are.