ndd -get /dev/tcp tcp_conn_hash
This value does not limit the number of connections, but it can cause connection hashing to take longer. The default size is 512.
To make lookups more efficient, set the value to half of the number of concurrent TCP connections that are expected on the server. You can set this value only in /etc/system, and it becomes effective at boot time.
Use the following command to get the current number of TCP connections.
netstat -nP tcp|wc -l