Windows 7 RC on my desktop machine is doing strange things with networking. Normally, it's the only machine on the network, served by a Draytek Vigor 2800. The setup has worked fine for a long time (like, years). Often, I connect my laptop (also running Win 7 RC) to the network, to synchronise stuff between it and the desktop. (Sometimes, I connect from other locations via VPN, and that works fine - no problems noted, but it doesn't stay connected for long) However, if I leave the laptop on its docking station at home, the desktop will at some point lose connection to it. The laptop can still see the desktop, and open shared folders on it. The desktop reports that the laptop isn't connected if I try to go that way. I've checked the network and sharing center, in its detailed layout, to see what's happening. That may indicate the problem. I don't know how to post images on here, but have uploaded them to my webspace. Hopefully, they can be seen. When just the desktop is connected, all looks normal - http://www.kirbycane.plus.com/wackynetwork0.jpg When I first switch on the laptop, it appears as expected, still all looking normal - http://www.kirbycane.plus.com/wackynetworkN.jpg After a while (several hours), the problem appears. The desktop can no longer access shared folders on the laptop. The laptop can still access the desktop. It appears that the desktop is now connected to the outside world VIA the laptop - http://www.kirbycane.plus.com/wackynetwork1.jpg If I then start the laptop's WiFi connection to the network (so it's connected twice), an unidentified device appears on the desktop, with the laptop's two connections shown separately. The laptop can still "see" shared stuff on the desktop, and the desktop still reports that the laptop isn't available - http://www.kirbycane.plus.com/wackynetwork2.jpg Can anyone suggest what's happening, or what to do?

When you connect the laptop to the network, do you connect the laptop and desktop directly with cross cable or AD hoc? We could not open the links you provided to see the screenshots. Please submit the screenshots in the SkyDrive of your Live Space. Then give us the link to the SkyDrive. Also, please run the following commands in command prompt with administrator privilege on the problematic computer when the issue occurs. ipconfig /all > %userprofile%\desktop\ipconfig.txtroute print > %userprofile%\desktop\routeprint.txt Please open the created files ipconfig.txt and routeprint.txt on Desktop, and paste the contents in your next post. Waiting for your reply.Arthur Xie - MSFT

When you connect the laptop to the network, do you connect the laptop and desktop directly with cross cable or AD hoc? Neither - each connects via Cat 5 to the Draytek router referred to above. We could not open the links you provided to see the screenshots. Please submit the screenshots in the SkyDrive of your Live Space. Then give us the link to the SkyDrive. I don't (as far as I know) have a SkyDrive or LiveSpace. Those links are to the files on my own webspace. Copying the bit from http:// to .jpg into a browser should display them. Also, please run the following commands in command prompt with administrator privilege on the problematic computer when the issue occurs. ipconfig /all > %userprofile%\desktop\ipconfig.txt Windows IP Configuration Host Name . . . . . . . . . . . . : Octavious-W7 Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No Ethernet adapter Bluetooth Network Connection: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network) Physical Address. . . . . . . . . : 00-02-5B-01-07-FC DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Realtek RTL8139/810x Family Fast Ethernet NIC Physical Address. . . . . . . . . : 00-0B-6A-92-30-A6 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IPv4 Address. . . . . . . . . . . : 192.168.8.110(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : 18 July 2009 22:39:45 Lease Expires . . . . . . . . . . : 23 July 2009 12:30:53 Default Gateway . . . . . . . . . : 192.168.8.1 DHCP Server . . . . . . . . . . . : 192.168.8.1 DNS Servers . . . . . . . . . . . : 192.168.8.1 NetBIOS over Tcpip. . . . . . . . : Enabled route print > %userprofile%\desktop\routeprint.txt =========================================================================== Interface List 12...00 02 5b 01 07 fc ......Bluetooth Device (Personal Area Network) 10...00 0b 6a 92 30 a6 ......Realtek RTL8139/810x Family Fast Ethernet NIC 1...........................Software Loopback Interface 1 =========================================================================== IPv4 Route Table =========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 192.168.8.1 192.168.8.110 20 127.0.0.0 255.0.0.0 On-link 127.0.0.1 306 127.0.0.1 255.255.255.255 On-link 127.0.0.1 306 127.255.255.255 255.255.255.255 On-link 127.0.0.1 306 169.254.0.0 255.255.0.0 On-link 192.168.8.110 296 169.254.255.255 255.255.255.255 On-link 192.168.8.110 276 192.168.8.0 255.255.255.0 On-link 192.168.8.110 276 192.168.8.110 255.255.255.255 On-link 192.168.8.110 276 192.168.8.255 255.255.255.255 On-link 192.168.8.110 276 224.0.0.0 240.0.0.0 On-link 127.0.0.1 306 224.0.0.0 240.0.0.0 On-link 192.168.8.110 276 255.255.255.255 255.255.255.255 On-link 127.0.0.1 306 255.255.255.255 255.255.255.255 On-link 192.168.8.110 276 =========================================================================== Persistent Routes: None IPv6 Route Table =========================================================================== Active Routes: If Metric Network Destination Gateway 1 306 ::1/128 On-link 1 306 ff00::/8 On-link =========================================================================== Persistent Routes: None

Meanwhile, I think I've fixed it. The pesky IPv6 had turned itself back on (I turned it off weeks ago, following advice on another thread). The network path shown on the desktop PC is still the same wacky one, with the desktop connecting to the "Unknown" device which connects to the laptop which connects to the router - this despite the fact that both desktop and laptop connect direct to the router. However, the desktop can now see the folders and files on the laptop (and vice-versa). They can both also now see the Linux machine and all the stuff on that. I'll keep watching, but I think the problem is that IPv6 doesn't work in my office. Since IPv4 works perfectly, I don't think I care.