I have a problem with Windows 7 RC (7100).
I frequently use a crossover network cable on WinXP with static IP addresses to connect to various industrial devices (e.g. robots, pumps, valves or even other Windows PCs) that have Ethernet network ports.
When I do this on Windows 7, the network connection is classed as an “Unidentified Network” in
Networks and Sharing Center and the public firewall profile is enforced by Windows. I do not want to change the public profile and would prefer to use the Home or Work profile instead.
For other networks like Home and Work I’m able to click on them and change the classification. This is not available for unidentified networks.
My questions are these:-
- Is there a way to manual override the “Unidentified Network” classification?
- What tests are performed on the network that fail, therefore classifying it as an “Unidentified Network”
By googling (hitting mainly vista issues) it seems that you need to ensure that the default gateway is not
0.0.0.0. I’ve done this. I’ve also tried to remove IPv6 but this does not seem possible on Windows 7.
For those still having problems here is the answer to my issue and the possible reasons why:-
Win7 keeps a list of the networks you visit by (I am assuming, but don’t know for sure) the MACID of the device pointed to by the Default Gateway. The default gateway is usually the constant device in a network (i.e. the NAT or router) so can be used to uniquely identify one network from another.
The default gateway in the IPv4 properties panel must therefore point to an actual endpoint so windows can then keep track of it. If there is a device at the end of the Default Gateway windows will identify it and track it remembering its settings.
The ways you can therefore fool Win7 is to either point the default gateway to your own IP address, or the IP address of the target device you’re communicating with. This will have the side effect of expecting that target device to start routing packets for IP destinations that are outside your subnet. So some applications on Win7 will try to communicate with the internet, these will be passed on to the default gateway (either back you the same IP address or a target device that is not a router) and thus will eventually timeout because neither can route packets. Which you can usually live with. This gets slightly complicated when you mix a this type of connection with a real connection to the internet via WIFI. The wired network card usually has priority when routing because of the “interface metric” so some applications might not connect correctly.