# Unknown device between computer and router



## Nevars (Jun 11, 2010)

DLink Wireless router. One pc laptop (wireless to router). One pc Tower on ethernet to router. Both machines have had Windows 7 installed recently. Previously, one was running Vista, one was XP.

On both computers, when I look at the network map I often see a "?" (unknown device) between the computer and the router. At the same time, devices on the other side of the router are either not seen at all, or are recognised but can't be put on the map.

For each computer I can go to "network adaptor", properties, and first select "TCP/IPV6" then click okay, and then undo that process by going in again and unselecting IPV6. Having done this, if I go back to the network map, everything is okay. The "?" in the map has gone, and the map is complete.

Note: I see my router as a single device, although just once it appeared as two devices - the router and a 'switch' - does anybody know what that is about?

What is going on? I also can't get my networking MX860 printer seen on the network, so I'm wondering if these problems are related.


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## JohnWill (Oct 19, 2002)

Post a screen shot of the network map and describe the equipment on the network.


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## Nevars (Jun 11, 2010)

The problem of "unknown device" persists, but I do have my MX860 printer working on the network now. That problem was caused because the driver install was not creating a BJNP port as it should have (on either of my computers). Now fixed, and works fine.

That said, I still get "unknown device problems on the network maps from both machines, exactly as described in my first question. I can temporarily fix these problems (as also described in my first question) the problem recurs. I think it is also linked to difficulties I have in sharing files on the computers (because they dont see each other).

I have a home network, with two computers both using Windows 7 Home Premium. Plus a Dlink wireless router and an MX860 network printer. The Laptop uses wireless to connect to the network, the Desktop machine links via ethernet and the MX860 printer is connected via ethernet.

*I have attached a series of screen shots that should help you to understand the arrangement, and the symptoms*. The screen shots are in a sequence, with the final screen shot being what the network map looks like when the network map on both machines is okay. To get to that stage, I have to apply then un-apply TCP/IPV6 on both machines. 

I hope this makes sense. I'd like to find out what is happening. Being a 'beginner' I don't know whether this is a real problem or just a minor glitch that does not matter. 

For example, now that my MX860 networked printer is operating successfully - why is it not visible on the network at all?
I am also struggling to access either machine from the other (to share files) despite being on the same homegroup and having sharing turned on etc.
Thanks, Nevars


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## JohnWill (Oct 19, 2002)

Let's see this from each of the two machines.

Hold the *Windows* key and press *R*, then type *CMD* then press *Enter* to open a command prompt:

In the command prompt window that opens, type type the following commands, one at a time, followed by the _*Enter*_ key:

_Note that there is a space before the -n or the /ALL, but there is *NOT* a space after the - or / in the following commands._

NBTSTAT -n

IPCONFIG /ALL

Right click in the command window and choose *Select All*, then hit *Enter* to copy the contents to the clipboard.
Paste the results in a message here.

If you are on a machine with no network connection, use a floppy, USB disk, or a CD-RW disk to transfer a text file with the information to allow pasting it here.


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## Nevars (Jun 11, 2010)

Hi again,

The info you asked for is attached.

I don't understand the information, but I can see quite different responses from the two machines to the NBTSTAT -n instruction. The Desktop has just one Network Adaptor (as indicated in the text). However the Laptop has three (LAC, Bluetooth, and Wireless) BUT it shows only two in the text).

Note also that the MX860 network printer is linked to the router as well, and is operating correctly from both computers. It does not show up on the network maps, though. Should it?

Hope this info helps. 

Nevars


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## JohnWill (Oct 19, 2002)

I suggest you enable DHCP on each of the machines, that may be a part of your issue.

*Configure DHCP for Windows Vista & Windows 7*


 Click on the Start menu, and select Control Panel.
 Click on Network and Internet. (Skip this step if you do not see this Control Panel item.)
 Click on Network and Sharing Center.
 Click on Manage network connections.
 Right click on Connection you wish to change and choose Properties. If Windows say it needs your permission to continue, click Continue.
 Select Internet Protocol Version 4(TCP/IPv4) and click Properties.
 Select Obtain an IP address automatically.
 Select Obtain DNS server address automatically.
 Click OK to close the TCP/IP Properties window.
 Click OK to close the Local Area Connection Properties window.
 Click Close to close the Network Connections window.
 Click Close to close the Control Panel window.
 Restart your computer.

If you still have issues, a stack repair might be in order.

*TCP/IP stack repair options for use with Vista or Windows 7.*

Start, All Programs\Accessories and *right click* on Command Prompt, select "*Run as Administrator*" to open a command prompt.

In the command prompt window that opens, type type the following commands, each followed by the Enter key:

Reset WINSOCK entries to installation defaults: *netsh winsock reset catalog*

Reset IPv4 TCP/IP stack to installation defaults. *netsh int ipv4 reset reset.log*

Reset IPv6 TCP/IP stack to installation defaults. *netsh int ipv6 reset reset.log*

Reboot the machine.


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## Nevars (Jun 11, 2010)

Thanks very much. I did all that.

In the connections, I did not have to change anything on either computer. On both, everything you described was already correct. DHCP was already enabled in both cases.

I then did the TCP/IP stack repairs you described, and rebooted.

I have not had the "unknown device" since. It is not always present, so I am still waiting. However I have restarted the computers several times since, so maybe it is fixed.

I am still puzzled that the MX860 printer is not shown in the nework maps - shouldn't it be? As a novice, I would have expected the network maps to show all networked devices. The printer is working fine.

However I do still have problems networking. Even when the network maps look okay, I can't actually access either computer from the other. I have spent hours setting up homegroup, filesharing etc, and still no ability to access between computers.

Have a look at the attached screen shots. They are all taken at the same time, when the network maps look fine. Although the Desktop shows the Laptop, it can't access it. The Laptop does not even show the Desktop.


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## JohnWill (Oct 19, 2002)

I wouldn't put much credence in the Network map. I've posted mine as an example, suffice to say that's not really how the network is tied together. 

As far as the networking, I'd lose the homegroups totally and configure networking like earlier versions of Windows. I have a mixed network, and I have no issues with Win7, Vista, XP, 2K, and Linux all playing together on the network. Try starting from scratch without homegroups and run through the following list.

Turn off any firewalls for debugging. If the firewall is the problem, you'll have to configure it to allow access to "trusted zone" addresses. Note that some firewalls must be completely uninstalled to stop them from affecting your networking.

Hold the *Windows* key and press *R*, then type *CMD* to open a command prompt.

In the command prompt window that opens, type type the following commands:

PING each remote computer by IP address, and if successful, PING by name. Open a command prompt as described above and type.

PING _<ip address>_ 
or
PING _<computer name>_

Where: 
_<ip address>_ - is the x.x.x.x IP address
_<computer name>_ - is the computer name

*A failure to PING is almost always a firewall configuration issue. Any failure to PING needs to be corrected before you go any farther.*

_*Note:* You can obtain the IP address and computer name of a computer by opening a command prompt (DOS window) and typing *IPCONFIG /ALL*. This should work for any Windows version. The IPCONFIG /ALL display will provide a wealth of useful information for debugging your network connection._

Check your Services are Started on all PCs: 

COM+ Event System (for WZC issues)
Computer Browser
DHCP Client
DNS Client
Network Connections
Network Location Awareness
Remote Procedure Call (RPC)
Server
TCP/IP Netbios helper
Wireless Zero Configuration (XP wireless configurations)
WLAN AutoConfig (Vista wireless configurations)
Workstation

_*Note:* You can check the services in Control Panel, Administrative Tools, Services._

All of these services should be started, and their startup type should be automatic.

If a service is not running, open it's properties and check the dependencies. Check each of the dependencies and see which one is preventing the service from running. Checking the event log is also a good idea here, there may be clues to what is failing.

All computers should be in the same workgroup for computer browsing to function properly. File & Print Sharing has to be enabled on any computer you wish to share files or printers from. You also need to actually share the resource in question from My Computer, right click on the drive/printer/folder, and select sharing.

If you encounter difficulties accessing computers that are visible in Network Places (_Network and Sharing Center in Vista_), make sure the computer being accessed has an account with the same name/password as the system connecting to it uses to login. NOTE: Vista's default is to require a password on the account to enable file/print sharing.

While the default NetBIOS setting is correct for normal network configurations, it's possible for it to be altered, and it costs nothing to make sure it's correct. NETBIOS over TCP/IP must be enabled for normal network browsing. You can open a command prompt as described above and type the following command: *nbtstat -n*. This will display the status of NetBIOS or indicate it's not configured.


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## TerryNet (Mar 23, 2005)

One of those connections--I think from the attachment in post # 5--has NetBIOS disabled. That's wrecking file sharing. In Network Connections right click on the connection - select TCP/IPv4 - Properties - Advanced - WINS tab - enable NetBIOS.


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## xHeero (Aug 1, 2009)

dont put too much stock in the network map, its not very accurate.


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