Linux_ System administration commands (frequently used in work)

2. View network configuration information ifconfig
4. View system Resource information (like win system Explorer) Top (ps:load average load Task process Cpus/mem Swap swap partition similar to win system virtual memory)
6. View Memory usage Free-m #-m represents the default KB in megabytes
8. View System Processes Ps-ef
10. View firewall status/etc/init.d/iptables status or CD/ETC/INIT.D;. /iptables status
12. Temporarily open firewall/etc/init.d/iptables start or service iptables start
14. Temporarily shut down the firewall/etc/init.d/iptables stop or service iptables stop
16. Permanently turn on the firewall chkconfig iptables on
18. Permanently shut down the firewall chkconfig iptables off
20. Restart Firewall settings Service iptables restart
22. Firewall Custom Port formatting:

    A input-m state–state new-m tcp-p tcp–dport 80-j ACCEPT (allow 80 ports through the firewall)

    Vi/etc/init.d/iptables

    Increase the port in the format above

    /etc/init.d/iptables Restart can

24. No ps-ef off when viewing tomcat | grep Tomcat
26. When you turn on Tomcat, view the boot information tail-f. /logs/catalina.out
28. Terminating tomcat Command kill-9 Tomcat_pid
30. Restart Network Service restart
32. View network status netstat (available to all users)

    -a query All-t query TCP (3 handshake, Secure) Information-u query UDP (only responsible for transmitting data, fast) information-L listening Port-R View Route (Gateway)-N IP Address port number

    NETSTAT-TUNL querying TCP and UDP network information that is listening

    Netstat-an Query all listening network information and connected network information

Linux_ System administration commands (frequently used in work)