Network address translation (NAT) is a method of remapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device. The technique was originally used to avoid the need to assign a new address to every host when a network was moved, or when the upstream Internet service provider was replaced

Network address translation (NAT) is a method of remapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device. The technique was originally used to avoid the need to assign a new address to every host when a network was moved, or when the upstream Internet service provider was replaced Network Address Translation (NAT) is the process where a network device, usually a firewall, assigns a public address to a computer (or group of computers) inside a private network. The main use of NAT is to limit the number of public IP addresses an organization or company must use, for both economy and security purposes. The NAT support for voice feature allows SIP embedded messages passing through a router configured with Network Address Translation (NAT) to be translated back to the packet. An application layer gateway (ALG) is used with NAT to translate the voice packets. For more information about implementing NAT with voice, refer to NAT Support for ALGs. Q. In the field of computer networking, NAT stands for N etwork A ddress T ranslation. In simplest terms, NAT allows many devices on a private network to share a single gateway to the internet. In turn, all of those devices will have the same public IP address —that of the gateway—and unique private IP addresses.These gateways are commonly found on wifi routers and some VPN services. Network Address Translation allows a single device, such as a router, to act as an agent between the Internet (or "public network") and a local (or "private") network. This means that only a single, unique IP address is required to represent an entire group of computers. But the shortage of IP addresses is only one reason to use NAT.

The NAT support for voice feature allows SIP embedded messages passing through a router configured with Network Address Translation (NAT) to be translated back to the packet. An application layer gateway (ALG) is used with NAT to translate the voice packets. For more information about implementing NAT with voice, refer to NAT Support for ALGs. Q.

R2 looks in NAT table to find out the actual IP address of the destination. Since the NAT table of R2 has an entry for the address 100.0.0.2 which maps it with the address 192.168.1.1, R2 will replace the destination address 100.0.0.2 with the address 192.168.1.1 and forward it to the web server.

• NAT (Network Address Translation) allows to use your own private IPv4 addressing system and prevent the internal address changes if you change the service provider. Disadvantages of NAT • NAT (Network Address Translation) is a processor and memory resource consuming technology,

NAT (Network Address Translation) Network Address Translation (NAT) is a term used to describe any of several forms of IP address and port translation. At its most basic level, NAT changes the IP address of a packet from one value to a different value. 2. Dynamic NAT. Instead of choosing the same IP address every time, this NAT goes through a pool of public IP addresses. This results in the router or NAT device getting a different address each time the router translates the local address to a public address. 3. PAT. PAT stands for port address translation. • NAT (Network Address Translation) allows to use your own private IPv4 addressing system and prevent the internal address changes if you change the service provider. Disadvantages of NAT • NAT (Network Address Translation) is a processor and memory resource consuming technology, Remember, if the NAT IP address or the ports are changed, the firewall rule may also need adjusting if a linked firewall rule was not chosen. Common things to check for: Correct interface: Usually WAN, or wherever traffic will enter the firewall. Correct NAT IP: The IP address must be reachable from an interface on the firewall. Network Address Translation (NAT) can be configured to work on your network a few different ways. The type of NAT you choose to implement depends on what your goals are for NAT and your public address management. NAT methods include Static NAT: Puts a permanent mapping between an internal private address and a public address. This extra NAT hides the source address of the client, making the traffic appear to originate from the firewall instead, so that the connection can be properly established. Split DNS is the best means of accommodating large port ranges and 1:1 NAT. Maintaining a split DNS infrastructure is required by many commercial firewalls even, and This article introduces the Network Address Translation (NAT)concept. Learn what Network Address Translation is, how it is used and the benefits it provides to networks, companies and workplaces of any size. Our unique award-wining network diagrams are used to help illustrate the operation and concept of NAT.