Use and understanding of iptables

The implementation of security groups in openstack neutron is based on iptables (of course it also supports openflow flow tables), so I want to deepen my understanding of iptables. Many people know iptables but not netfilter. iptables is essentially just a firewall management tool on Linux, located in /sbin/iptables. Netfilter is the real implementation of […]

iptables usage example

1.iptables parameters -t: Specify the table to be manipulated; -A: Add entries to the rule chain; -D: Delete entries from the rule chain; -i: Insert an entry into the rule chain; -R: Replace entries in the rule chain; -L: Display existing entries in the rule chain; -F: Clear existing entries in the rule chain; -Z: […]

A062-Firewall security configuration-Configuring Iptables firewall policy

Experimental steps: [Teaching Resource Category] Serial number Category Tick√ 1 Learning Resources √ 2 Individual soldier mode competition question resources 3 Group competition question resources [Teaching resource name] Firewall security configuration – configure security settings iptables firewall policy [Teaching Resource Classification] First level category Second level categories Tick√ 1.Safety standards laws and regulations Industry Standard […]

The principle and function of iptables firewall and access control

iptables firewall Article directory iptables firewall Starting and stopping the firewall netfilter View firewall default rules Rule table Matching process The firewall matching rules are four tables and five links. basic grammar Common control types monitor implicit match Ban ping host ip delete rule Enable forwarding Export firewall rules Backup rules Import firewall backup rules […]

Redsocks traffic forwarding combined with iptables traffic transparent transmission under Linux appears socket: Too many open files and connect: Bad file descriptor

Under Linux, redsocks traffic forwarding combined with iptables traffic transparent transmission appears socket: Too many open files and connect: Bad file descriptor. Oct 8 18:59:34 localhost redsocks[26193]: connect: Bad file descriptor Oct 8 18:59:34 localhost redsocks[26193]: [192.168.10.10:53318->124.225.191.19:443]: red_connect_relay: Bad file descriptor Oct 8 18:59:34 localhost redsocks[26193]: [192.168.10.10:53318->124.225.191.19:443]: dropping client (R/W), relay (R/W), idle 0.000234s Oct […]

Security technology and iptables firewall

1. Security technology 1.1 Overview 1. Intrusion detection mechanism: It is characterized by blocking, quantifying, and locating network threats from inside and outside. Provide alarm and post-event supervision. Similar to monitoring. 2. Intrusion prevention: Works in transparent mode, analyzes the content of data packets, protects all content entering the machine, analyzes and determines Trojans, worms, […]

Linux firewall iptables (Part 1)

What is a firewall Firewall (English: Firewall) technology helps computer networks connect internal and external networks by organically combining various software and hardware devices for security management and screening. A technology that builds a relatively isolated protective barrier to protect the security of user data and information. Classification of security technologies 1. Intrusion detection mechanism […]

[iptables practice] 07 iptables NAT experiment

In the previous section, we forwarded the machines on the two network segments through the network of the intermediate machine to achieve interoperability. Let’s review this network connection diagram again In the previous section, in the firewall experiment, we set the forwarding rules of host B. We first clear the forwarding rules of host B. […]