Mikrotik Router NAT (Network Address Translation)

Network Address Translation: NAT  is a methodology of mapping  Private  ip address to another Public  ip address. Actually, private ip address can’t pass through internet without NAT. NAT provides of mapping between private ip address to route able public ip address. There  are many kind of NAT and to implement depends on what our goals are for NAT and our public ip address management.
·         Static NAT (One to One mapping):One to one mapping is also called static NAT it’s put a permanent ip mapping between an private ip address and a public  ip address.
·         NAT Overloading: It’s called Port Address Translation or PAT.In this case multiple private ip address space are able to share a common public ip address. Port address translation is reducing number of public ip address for network address translation.
·         Dynamic  NAT: Another  NAT method are Dynamic NAT. Dynamic map puts a dynamic mapping between an internal private ip address pool and a public ip address pool.It’s also create one to one relation on a FIFO algorithm basis .This method mikrotik router  called netmap.
NETMAP Configuration Example:
/ip firewall nat add  chain=dstnat action=netmap to-addresses=172.16.0.0/16
      dst-address=1.1.1.0/25 log=no log-prefix=""

/ip firewall nat add  chain=srcnat action=netmap to-addresses=1.1.1.0/25
      src-address=172.16.0.0/16 log=no log-prefix="
This configuration tell us a pool of ip address that are 172.16.0.0/16 mapped between a pool of an public ip address that are 1.1.1.0/25 is dynamically.