What is the different between NAT and PAT ? Where to use each of them ? and why ?

NAT Means Network Address Translation and PAT means Port Addess Translation. NAT and PAT used for Public to Private IP Translation.

NAT work for convert LAN user IP request to Public Server IP address. PAT also work like that, But have some different. PAT work with Port Number.

Hi,

NAT is the process of converting private IP or IPs to Public IP or IPs or convering public IP or IPs to private IP or IPs, in many cases and scenarios NAT is ued to convert private to public.

There are three types of NAT:

1. Static NAT  convert one private IP to one public IP

2. Dynamic NAT convert group of private IPs to group of public IPs

3. PAT or Port Address Translation convert group of private IPs to one public IP and is used to allow large number of computers have privae IPs to access internet with using single public IP, in PAT every source computer of all computer is assigned a number randomly generated from the range in L4 to be able to access the internet.

HTH

Best Regards,

NAT: Network Address Translation is a mechanism for translating private addresses into publicly usable addresses to be used within the public internet, it generally only translate IP addresses on a one to one correspondence between publicly exposed IP addresses and privately held IP addresses. PAT: Port Address Translation or NAT overloading maps multiple private IP addreses to a single or a few public IP addresses by tracking each private address by a port number. With IP V4, PAT is what most NAT devices do.

Network Address Translation is a way of representing multiple ip address into single ip address or group of ip address. there are three types of NAT :

1- Static : one-to-one address translation

2- Dynamic: multiple-to-multiple address translation

3- PAT : multiple-to-one address translation.

mostly NAT is used when:

* There is a need to connect many hosts to internet, and you do not have globally unique addresses for all of them.

* Your company changed to new ISP that require you to renumber your network.

* You need to merge two or more intranets with duplicate address.

NAT: Network Address Translation is a mechanism for translating private addresses into publicly usable addresses to be used within the public internet, it generally only translate IP  PAT: Port Address Translation or NAT overloading maps multiple private IP addreses to a single or a few public IP addresses by tracking each private address .but pat is more popular than nat as is uses ports