Netstat is a command line utility program. It provides useful information about the current TCP/IP settings of a connection.
For Class A, there are 126 possible networks and 16,777,214 hosts For Class B, there are 16,384 possible networks and 65,534 hosts For Class C, there are 2,097,152 possible networks and 254 hosts
Clustering support refers to the ability of a network operating system to connect multiple servers in a fault-tolerant group. The main purpose of this is the in the event that one server fails, all processing will continue on with the next server in the cluster.