iptables multiport

The default script only enables port 80, 3306, and port 22 of the conventional web server # videfault_firewall.sh #! /Bin/bash #################################### ####################################### File: the default default_firewall.sh script only enables ports 80, 3306, and 22 of the conventional web server. # Vi default_firewall.sh #! /Bin/bash ######################################## ################################# # # File: default_firewall.sh # Description: # Language: GNU Bourne-A

CentOS Study Notes-firewall iptables, centosiptablesLinux Firewall: iptables Iptables is a packet filtering software, and more than 2.6 of the Linux kernel is this software. This Section selects the Linux private dish of laruence-Chapter 9 server setup, firewall and NAT ServerPacket entry process: Importance of Rule Order! Assume that your Linux host provides

Netfilter/iptablesIs an IP information packet filtering system integrated with the latest Linux kernel version 2.4.x. If the Linux system is connected to the Internet or LAN, server, or a proxy server connected to the LAN and Internet, the system facilitates better control of IP packet filtering and firewall configuration on the Linux system. Mugdha vairagade will introduce the Netfilter/iptables system, how it works, its advantages, installation and

Iptables is a packet filtering management tool based on the NetFilter architecture, the most important role is to do firewall or transparent proxy. Iptables from IPChains, its function is more powerful. Iptables offers the following three features: packet filtering, NAT (network address translation), and generic Pre-route packet mangling. In the previous article

1. start and close iptables. iptables will be officially used to create a firewall. The method for starting and disabling iptables depends on the Linux release version in use. you can first view the documentation of the Linux version in use. Generally, iptables is included in the Linux release. run

0x00 iptables Introduction The package filtering function of linux is the linux firewall, which consists of netfilter and iptables. The netfilter component, also known as the kernel space, is a part of the kernel. It consists of information packet filtering tables that contain the rule set used by the kernel to control information packet filtering. The iptables c

For this article, we will use iptables user space tool Version 1.2.6a and kernel version 2.4.9. Linux security and Netfilter/iptablesLinux has become very popular in the IT industry because of its robustness, reliability, flexibility, and customization that seems unlimited. Linux has many built-in capabilities that allow developers to customize their tools, behaviors, and appearances based on their own needs, without the need for expensive third-party

First, install the software We buy VPS, generally have pre-installed iptables, you can check the status of the Iptables, confirm whether the installation. Service Iptables status If prompted for iptables:unrecognized service, you need to install. Yum Install iptables #CentOS系统apt-get install

Tags: firewall iptables firewalldOne, iptables and firewalld comparisonIn the CentOS 7 system, the FIREWALLD firewall replaces the iptables firewall. In fact, iptables and FIREWALLD are not real firewalls, they are just firewall management tools or services that define firewall policies.The

Commands in iptables must be case sensitive. The main syntax differences between ipchains and iptables are as follows: 1. In ipchains, for example, the input chain uses a lowercase name. In iptables, use uppercase input instead. 2. in iptables, you must specify the rule to be applied to that rule table (use-t to specif

Introduction: A Good article about the Linux firewall iptables configuration, Linux firewall configuration is critical, this involves the server security, security is not absolute, but iptables with good can eliminate most of the gray temptation. Reprinted to the Old Bar blog, more iptables configuration can consult the author.Linux

If your iptables basic knowledge is not yet known, it is recommended to take a look first.Start ConfigurationLet's configure a firewall for the filter table.(1) Check the setting of this institution in Iptables[email protected] ~]# iptables-l-NChain INPUT (Policy ACCEPT)Target prot opt source destination Chain FORWARD (policy ACCEPT)Target prot opt source destina

Introduced Iptables is an IP packet filtering system integrated with the latest version 3.5 Linux kernel. If a Linux system is connected to an Internet or LAN, a server, or a proxy server that connects LAN and the Internet, the system facilitates better control over IP packet filtering and firewall configuration on Linux systems. Management control options for the iptables command -A (append) adds a new

CAT/etc/sysconfig/iptables * Filter: Input accept [0: 0]: Forward accept [0: 0]: Output accept [28: 4192]-A input-p tcp-m tcp -- dport 22-M state -- state new, established-J accept-A input-p tcp-m tcp -- dport 21-M state -- state new, established-J accept-A input-p tcp-m tcp -- dport 20-M state -- state new, established-J accept-A input-J reject -- reject-with ICMP-host-prohibited-A forward-J reject -- reject-with ICMP-host-prohibitedCommit

The previous script is in save mode, now attach the command to a file, so that it can be easily modified two times or somethingThe script is basically like this, we can change with their situation again ~ add function or something. Copy Code code as follows: #!/bin/bash While True Todo Clear echo "----------------------Menu----------------------" echo "(1) Service iptables restart" echo "(2)

/modprobe. d/vsftpd. conf Alias ip_conntrack ip_conntrack_ftp ip_nat_ftp -- load the FTP Module Vim/etc/rc. Local /Sbin/modprobe ip_conntract -- boot Module/Sbin/modprobe ip_conntrack_ftp/Sbin/modprobe ip_nat_ftp 4. Port Filtering Vim/etc/sysconfig/iptables -A input-p tcp-M multiport -- dport 20, 21-M state -- state new-J accept -- enable port 20 and port 21-A input-p tcp-M state -- state n

composition of the iptables (four-sheet five-strand)TableFilter: Filtering PacketsNAT: The source or destination address of the transform packetMangle: Used to mangle the package, changing the properties of the packageRaw: A link-tracking process used to not allow iptables to do packets, mainly to improve performance* Priority: Raw>mangle>nat>filter (Please note the priority level)ChainINPUT: Modify the pac

I. required command: view the configuration information iptables-L-n. remember to save/etc/init. d/iptablessave and add the input record iptables-AINPUT-ptcp? Dport22-jACCEPT add output records iptables-AOUTPUT-ptcp? Sport22-jACCEPT default port for some software: for ftp I. required commands: View configuration information I