Quick HOWTO : Ch14 : Linux Firewalls Using iptables

iptables is a command line interface used to set up and maintain tables for the Netfilter firewall for IPv4, included in the Linux kernel. The firewall matches packets with rules defined in these tables and then takes the specified action on a possible match. Tables is the name for a set of chains.; Chain is a collection of rules.; Rule is condition used to match packet. Iptables Introduction and Examples - LinuxAdmin.io May 07, 2017 iptables vs nftables: What’s the Difference? Another justification for a new utility is that the iptables framework has become a little convoluted with iptables, ip6tables, arptables, and ebtables all providing different but similar functions. For example, it’s simply inefficient to create IPv4 rules in iptables and IPv6 rules in ip6tables and keep the two in sync. IPTables Example Configuration - NetworkLessons.com

iptables: Linux firewall rules for a basic Web Server

iptables. Linux iptables command examples. iptables. Iptables is a name given to a configuration utility that is used to configure tables provided by the Linux kernel Firewall. Dec 24, 2017 · Example of iptables Rules allowing any connections already established or related, icmp requests, all local traffic, and ssh communication: [root@server ~]# iptables -L Chain INPUT (policy DROP) target prot opt source destination ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT icmp -- anywhere anywhere ACCEPT all -- anywhere anywhere ACCEPT tcp -- anywhere anywhere state NEW Jul 08, 2020 · iptables -F INPUT: iptables -F OUTPUT: iptables -X # Setting default filter policy: iptables -P INPUT DROP: iptables -P OUTPUT DROP: iptables -P FORWARD DROP # Allow unlimited traffic on loopback: iptables -A INPUT -i lo -j ACCEPT: iptables -A OUTPUT -o lo -j ACCEPT # Accept inbound TCP packets: iptables -A INPUT -m state --state ESTABLISHED How to list all rules from the Filter table of iptables? As I mentioned, the filter table is the default Iptables table. We can simply mange this table with out specifying the table name. See the examples pasted. Syntax: iptables -t filter --list or iptables -t filter -L Or simply; iptables --list or iptables -L Sample output:

A Sample Firewall Configuration - faqs.org

# Basic iptables/IPv4 template for an ordinary servers # # This file is in iptables-restore format. See the man pages for # iptables-restore(8) and iptables-save(8). # # The following is a set of firewall rules that should be applicable to Linux # servers running within departments. It is intended to provide a useful