nat for dummies

1. Nat Nat is short for net address translation. It can be seen from the name that it is a protocol responsible for network address translation. In general, it is responsible for converting the IP addresses and ports in the private network into public IP addresses and ports, even if we usually call the IP addresses. For example, a company generally has a private network, which is assumed to be a network seg

Part 1: Nat Introduction Various types of NAT (according to RFC) Full cone NAT: The Intranet host establishes a UDP socket (localip: localport). When the socket is used to send data to the external host for the first time, Nat will allocate a public network (publicip: publicport) to it ), in the future, this pair (publ

Abstract:This article is a companion article on "using iptales to implement a firewall with excessive packets". It mainly introduces how to use iptbales to implement powerful Nat functions under linux2.4. For more information about the syntax of iptables, see the article "using iptales to implement a firewall with excessive packet forwarding rate. What needs to be affirmed is that this article is definitely not a simple repetition of the

Inside-to-Outside ? If IPSec then check input access list ? Decryption-for CET ? Check input rate limits ? Input accounting ? Policy routing ? Routing ? Redirect to web cache ? NAT inside to outside (local to global translation) ? Crypto (check map and mark for encryption) ? Check output access list ? Inspect (Context-based Access Control (CBAC )) ? TCP intercept ? Encryption Outside-to-Inside ? If IPSec then check input access list ? Decryption-for

Currently, network security and network address translation are widely used. For any of these technologies, it is very good. Many people are thinking about how to share two good technologies but make them safe. Network Security (IPsec) and Network Address Translation (NAT) are widely used, but it is not easy to make them run together. From the IP point of view, NAT modifies the lower layer of the IP address

This article describes how to use iptbales to implement the powerful NAT Function under linux2.4. For more information about the syntax of iptables, see the article "using iptales to implement a firewall with excessive packet forwarding rate. What needs to be affirmed is that this article is definitely not a simple repetition of the NAT-HOWTO or the Chinese version, in the whole narrative process, the autho

About Slackware 9.1.0 System Configuration of firewall and NAT FunctionsDate: 2004/07/30 Author: zcatlinux Source: zclinux **************************************** ******************************************************************************** ***************** The system is mainly used for static nat ing and port access control on internal servers. In the firewall, the above firewall script has been aut

I. Lab Objectives Understand the principles and functions of NAT network address translation; Master static Nat configurations to enable LAN access to the Internet; Ii. Lab background To publish the WWW Service, the company now requires that the Intranet web server IP address be mapped to a global IP address to allow external networks to access the company's internal web servers. Iii. T

This section is mainly to analyze the NAT module-related hook function and target function, mainly to clarify the principle of NAT module implementation. 1.NAT-related hook function analysis NAT module is mainly in the nf_ip_prerouting, nf_ip_postrouting, Nf_ip_local_out, nf_ip_local_in four nodes on the

Three network connection modes on vmwarevm: bridged, host-only, and NATVMWare provides three working modes: bridged (bridging mode), NAT (network address translation mode), and host-only (host mode ). To apply them properly in network management and maintenance, you should first understand the three working modes. 1. bridged (Bridging Mode) In this mode, the Virtual Operating System of VMWare is like an independent host in the LAN, which can access an

**************************************** * ************************ About firewall system recovery operations and startup methods ***** **************************************** **************************************** **************************************** ******** ** ******************* ** **************************************** ***************** The system is mainly used for static nat ING and port access control on internal servers. In the firew

Iptables firewall and NAT service 1. overview 1. introduction (1) a combination of components set between different networks or network security domains, which enhances the security of the internal network of the organization (2) each packet passes review, determine whether a matching filtering rule exists. compare the rules one by one until one rule is satisfied. IptablesFirewall and NAT service1. Overview

security-zone Untrust interfaces ge-0/0/0.0 host-inbound-traffic system-services p IngNote: By default, ICMP is required to be released, except for business ports that are not managed to be ping-through.Second, Juniper SRX NAT1. Types of NAT1.1 Source Nat:interface1.2 Source NAT:p Ool1.3 Destination NAT1.4 Static NAT2. Configuration Example2.1 Interface-based source NAT[Email protected]# Set security NAT s

NAT principles of IPv6 and MAP66 1. Why is NAT not recommended in IPv6 standards? This is a problem. As I explained earlier, IPv4 NAT breaks the Internet's "interconnection" feature, making some IP addresses no longer accessible in two directions, NAT adds a direction to the IP protocol without direction, especially th

NAT is generally divided into SNAT, DNAT, and PNAT. This article mainly describes how to configure NAT using iptables. Therefore, the differences between the three NAT methods and the application scenarios are briefly described as follows: the destination address of the source address translation remains unchanged. rewrite the source address and create a

business logic and provides comprehensive and intelligent services for customers to achieve business customization and business-related management functions, such as business authentication and billing. Ii. penetration problems in NGN broadband access In NGN broadband access, the main concern is the broadband access problem at the edge access layer in NGN. Because the core bearer network and broadband access of NGN are built on the existing IP network, access users must be addressed through IP

: // python.org ')# Return_str = conn. Read ()# Print return_str Import urllib2 Def get_proxy_opener (proxyurl = 'HTTP: // route: 80', proxyuser = "aaaex \ aeejshe", proxypass = "hejinshou", proxyscheme = "HTTP "):Password_mgr = urllib2.httppasswordmgrwithdefaultrealm ()Password_mgr.add_password (none, proxyurl, proxyuser, proxypass) Proxy_handler = urllib2.proxyhandler ({proxyscheme: proxyurl })Proxy_auth_handler = urllib2.proxybasicauthhandler (password_mgr) Return urllib2.build _ opene

Huawei dynamic NAT configuration Test requirements:1) convert the internal network 10.1.1.0/24 to the public network address 200.1.1.1 ~ 200.1.1.10/28 surfing the Internet (accessing server3) and packet capture Analysis2) Verify that dynamic Nat is unidirectional. Environment deployment:PC1:IP: 10.1.1.1/24GW: 10.1.1.254/24Client1:IP: 10.1.1.2/24GW: 10.1.1.254/24Client2:IP: 100.1.1.1/24GW: 100.1.1.254/24Ser

The sum of the following NAT and STATIC commands for PIXASA compiled by the old arm: dynamic translation --- NAT: # nat (inside) 110.0.0.0255.255.255.0 # global (outside) 11900000.20-192.168.0.254netmask0000255.255.0 will 10. x network segment to 192.168.0.20-254 this ip address pool does not convert the address :( config) The following

Many people may not be very familiar with the NAT router principle, so I have studied the NAT router principle and precautions in its application. I would like to share with you here and hope it will be useful to you. IP address depletion facilitates the development of CIDR, but the main purpose of CIDR development is to effectively use the existing internet address. At the same time,