What are the types of NA? What are the types of NAT

1. Static nat:

It refers to the conversion of the private IP address of the internal network into a public IP address, the IP address pair is one-to-one and is immutable, and a private IP address is only converted to a public IP address. With the help of static conversion, it is possible to achieve access from the external search department network to some specific Paikai devices (such as servers) in the internal network.

2. Dynamic NAT:

When converting a private IP address from an internal network to a public IP address, the IP address is indeterminate and random, and all private IP addresses authorized to access the Internet can be randomly converted into any specified legitimate IP address.

3. Comprehensive NAT:

That is, port address translation adopts port multiplexing. All hosts on the internal network can share a legitimate external IP address to achieve access to the Internet, so as to maximize the saving of IP address resources. In front of Sega.

NAT Apps

Static NAT is manually set up to enable communication from Internet customers to be mapped to a specific private network address and port. Static mapping is necessary if you want computers connected to the Internet to be able to use servers (such as servers) and applications (such as games) on a private network. Static mappings are not removed from the NAT transformation table.

If there is a mapping in the NAT transformation table, then NAT is simply a one-way transfer of data from the Internet to the private network. In this way, NAT provides some level of protection for computers connected to the private network portion. However, if you consider the security of the Internet, NAT needs to be used in conjunction with a full-featured firewall.

Full Cone NAT: All requests from the same internal Tuple X are translated to the same external Tuple Y, regardless of whether they belong to the same application or multiple applications.

In addition, when the X-Y translation relationship is established, any external host can send UDP packets to the internal host at any time with the address and port in Y as the destination address and destination port.

When terminal C after this type of NAT sends a message to server S and starts a connection, NAT assigns a port P to C and binds P to C. After that, NAT will give it to C, regardless of whether the request is from S or not, as long as it is sent to port P.

Network Address Translation (NAT) is a kind of access wide area network (WAN) technology, which converts private (reserved) addresses into legitimate IP addresses, and is widely used in various types of Internet access methods and various types of networks. The reason is very simple, NAT not only perfectly solves the problem of insufficient LP address, but also can effectively avoid attacks from outside the network, hide and protect the computer inside the network, although NAT can be achieved with the help of some ** servers, but considering the cost of computing and network performance, many times it is implemented on the router.

As the number of computers connected to the Internet continues to skyrocket, IP address resources are becoming more and more stretched. In fact, with the exception of the China Education and Research Computer Network (CERNET), the average user can hardly apply for a full range of Class C IP addresses. In other ISPs, even large LAN users with hundreds of computers are assigned only a few or a dozen IP addresses when they apply for an IP address.

Obviously, such a small number of IP addresses simply cannot meet the needs of network users, so NAT technology was born.

In the past, Internet access was mainly divided into two modes: ** and NAT (Network Address Conversion), but now NAT Internet access is mainly used. There are three types of NAT: StaticNAT, Poolednat, and PAT.

3. PAT maps the internal address to the different ports of an IP address of the external network.

The full name of NAT in English is "network address translation", which means "network address" in Chinese.

Translation", which is an IETF (Internet Engineering Task Force) standard that allows an entire organization to appear on the Internet with a public IP (Internet Protocol) address. As the name suggests, it is a type of internal private network address (IP address.

Technology translated into a legitimate network IP address.

NAT (Network Address Translation) was proposed in 1994. The NAT method can be used when some hosts in a private network have been assigned a local IP address (i.e., a dedicated address that is only used within the private network), but now want to communicate with the host on the Internet (without encryption).

This method requires the installation of NAT software on a router with a private network connected to the Internet. A router with NAT software is called a NAT router, and it has at least one valid external global IP address. In this way, all hosts that use a local address will have to translate their local address into a global IP address on the NAT router to connect to the Internet when communicating with the outside world.

In addition, this method of representing a large number of private IP addresses by using a small number of public IP addresses will help slow down the depletion of available IP address space. There is a description of NAT in RFC 1632.

1.Static SNAT

2.Network address port translation, also known as reverse NAT

3.Dynamic address NAT