check_connecting_status.md

How to check connecting status Back

1. The summary of sockets:

   ss -s 
   

2. Statistic of connections to a specific port like 80:

   netstat -nat | grep -i "80" | wc -l
   

3. Statistic of connections to a specific protocol like httpd:

   ps -ef | grep httpd | wc -l 
   

4. Statistic of established connections:

   netstat -na | grep ESTABLISHED | wc -l 
   

5. Statistic of connections sorted by IP:

   netstat -ntu | awk '{print \$5}' | cut -d: -f1 | sort | uniq -c | sort -n 
   

6. Statistic of top 10 visited urls via Nginx:

   cat /var/log/nginx/access.log | awk '{print \$7}' | sort | uniq -c | sort -nr | head -n 10 
   

7. Statistic of top 10 IPs to visit via Nginx:

   cat /var/log/nginx/access.log | awk '{print \$1}' | sort | uniq -c | sort -nr | head -n 10 
   

8. Statistic of top 10 time periods to visit via Nginx:

   cat /var/log/nginx/access.log | grep -P "\[{1}(.+)]" -o | cut -c 14-15 | sort | uniq -c | sort -nr | head 
   

9. Statistic of TCP connections grouped by their state:

   netstat -tan | grep ^tcp | awk '{++a[\$6]} END{for (i in a) print i, a[i]}' 
   

   • TIME_WAIT: Waiting for enough time to pass to be sure the remote TCP received the acknowledgment of its connection termination request.
   • CLOSE_WAIT: Waiting for a connection termination request from the local user.
   • ESTABLISHED: An open connection, data received can be delivered to the user. The normal state for the data transfer phase of the connection.
   • LISTEN: Waiting for a connection request from any remote TCP end-point.