If there two buildings each one has 100 floor and connected to network both are in the same server, and somewhere network been lost, how to determine the the error from which building?
First Of all , I believe you are considering zoning approach when you was designing your network . secondly, Any network monitoring software can help you to find out .
Any number of ways. One manual way is to attempt ICMP PING tests to routers in the two building networks, to see what is still connected and what is not. Another way is to set up periodic status messages that inform an operator of overall network status. For example, you can set up periodic IP multicast status messages, that you can then monitor from any point in the two buildings. Or for that matter, you can also automate the PING tests, and not use IP multicast for this.
No matter how the automated tests are carried out, you can then provide a graphic to an operator, showing the network components that are on line and those that don't respond.