Cisco Support Community
Community Member

Static NAT

I knew the concept and configuration of NAT and my confusion is :

for example : static (inside,outiside) netmask

my confusion is the 'netmask' in syntax because static NAT is a one 2 one solution that we can use,

so what is the advantage of using subnet mask ? is it for binding a valid subnet to a privet subnet ?

or is it for binding a public one IP addr to a private subnet? or somthing else, then if its for binding

subnet to subnet then how static NAT works ?



Re: Static NAT

Hi Sayed,

The purpose of the subnet mask is to give the range of addresses to be statically translated.

I am going to giev you an example...

static (in,out) netmask

The above NAT translates the internal to and this is indeed a one-to-one translation.

static (in,out) netmask

The above NAT translates the entire to

static (in,out) netmask

The above NAT translates to

So, you see that the static NAT is a static translation but it can include an entire subnet or just specific IPs.

Hope it helps.


Community Member

Re: Static NAT

Hello Dear Federico,

thanks for your usefull explanation, it has clarified my confusion but a little more clarification needs :


when we run static Nat command ( one 2 one )then the xlate table builds and we can see which real IP is binded to which mapped IP by show xlate command.

but when we run a static command that binds a subnet 2 subnet then its shows by show xlate just a subnet binded to a subnet and its not clear that which real IP of the private subnet is binded to which mapped IP of the public subnet.

- so is it automatically binds the private subnet IPs to Public subnet IPs respectively ? bcz it should be clear when we wants to publish a server to internet that which private IP is binded to which Public IPs in the range of two subnets ?!!.

- in case that we want to bind a subnet 2 subnet, then can we use Static PAT ? or its just possible with static NAT only ?

so please give me more information.



CreatePlease to create content