How do I use Iptables in Linux?

Owned by Galen Dove (Unlicensed)
Last updated: Mar 31, 2020 by Tenyo Grozev (Unlicensed)
1 min read

Problem

I need to setup iptables on my spinup server

Solution

Iptables is a utility that comes standard in secure linux servers.  It provides a host-level firewall that is separate from any external firewalls (security group in amazon, or yale's firewall in our datacenters).

Note that if you are using a server in a high-risk space (from CIS image) iptables is used on both CentOS and Ubuntu servers, i.e. Ubuntu does not use ufw and it will show inactive.

Please follow any of these guides for assistance with setting up iptables
  1. https://wiki.centos.org/HowTos/Network/IPTables
  2. https://www.digitalocean.com/community/tutorials/iptables-essentials-common-firewall-rules-and-commands

Best Practices

  • Keep iptables enabled on any server that needs to be secure
  • Only allow particular IPs and ports. Do not just allow everything (0.0.0.0/0)
  • Save your Iptables rules after modification . "sudo service iptables save"