Linux server maintenance --- count connections to view external connection ip addresses

Linux server maintenance-count the number of connections to view the external connection ip-Linux Enterprise Application-Linux server application information. For details, see the following. Server statistics:
1) count the number of connections on port 80
Netstat-nat | grep-I "80" | wc-l
1
2) count the number of httpd connections
Ps-ef | grep httpd | wc-l
1
3) collect statistics on connected instances in the "established" status'
Netstat-na | grep ESTABLISHED | wc-l
2
4) Find out which IP Address has the most connections and seal it.
Netstat-na | grep ESTABLISHED | awk '{print $5}' | awk-F: '{print $1}' | sort | uniq-c | sort-r + 0n

Netstat-na | grep SYN | awk '{print $5}' | awk-F: '{print $1}' | sort | uniq-c | sort-r + 0n