iptables command HowTo - Linux / Unix Q & A from nixCraft

How to add comments to iptables rules on Linux

last updated May 30, 2018 in CentOS, Debian / Ubuntu, Iptables, Linux, RedHat and Friends, Suse

I am a new Linux sysadmin. How can I add comments to iptables rules on Linux using the iptables command?

How to use or specify multiple IP addresses in iptables source or destination on Linux

last updated June 29, 2017 in CentOS, Debian / Ubuntu, Iptables, Linux, RedHat and Friends, Suse

I need to specific multiple IP address in iptables using Linux script. How do I create a rule that uses multiple source or destination IP addresses ?

Linux Iptables Delete postrouting Rule Command

last updated June 28, 2016 in CentOS, Debian / Ubuntu, Iptables, Linux, RedHat and Friends, Suse

I am a new Linux server sysadmin. I need to delete POSTROUTING rule. How do I delete postrouting rule on Linux server?

How to list all iptables rules with line numbers on Linux

last updated January 22, 2018 in CentOS, Debian / Ubuntu, Iptables, Linux, RedHat and Friends, Suse

I recently added NAT rules on my RHEL 6.x system. How do I see the rules including line numbers that I just added in Linux?

Ubuntu: Stat / Stop / Restart Iptables Firewall Service

last updated May 7, 2015 in Commands, Iptables, Ubuntu Linux

I am a new Ubuntu Linux version 12.04 LTS user. How do I stop or start iptables based firewall service on Ubuntu Linux using bash command line options?

Nginx: Block URL Access (wp-admin/wp-login.php) To All Except One IP Address

last updated April 14, 2013 in Linux, Nginx, Security, UNIX, Wordpress

I am the small business owner and runs my own web-site. I have noticed increased cracking activity against by blog. What’s the best way to block WordPress URLs such as example.com/blog/wp-login.php and example.com/blog/wp-admin/ in the nginx web-server?

Linux: Iptables List and Show All NAT IPTables Rules Command

last updated August 17, 2017 in CentOS, Debian / Ubuntu, Iptables, Linux, Suse

I am using /sbin/iptables -L -v -n | more command. However, I am unable to list NAT rules. How do I use the iptables command to view or list NAT rules stored in NAT tables? How do I see all the rules in NAT tables under CentOS / RHEL / Debian / Ubuntu Linux based server?