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RV180: Why I have to use one-to-one NAT setting while I can have DNAT setting in access rules?

Unanswered Question
May 25th, 2012
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Sorry to my dummy question.

Most of the people set the access rules and one-to-one NAT together.

But I found that in RV180, A DNAT can be set to bind the public ip to an internal ip in an access rule, seems the function is very similar to one-to-one NAT.

So, why I have to use one-to-one NAT anymore?

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davidagu Fri, 05/25/2012 - 10:37
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Hello Taylor,

Thank you for the questions.

Access Rules with DNAT and One-to-One NAT perform the same features: they can both allow an internal device to be accessible from the internet using an internet address.

One-to-One NAT forwards all ports to the internal device. An access rule with DNAT forwards specific ports or port ranges. For example, you could setup a one-to-one NAT rule for your server. All ports would be forwarded to the server on the respective public IP address. Or, you could setup DNAT rules to forward only specific ports. For example, ports 25, 80, and 443.

A DNAT rule denies everything but what you specify. A one-to-one NAT rule allows everything. If you only need to forward specific ports, then DNAT access rules are the best option.

-David Aguilar

Cisco Small Business Support Engineer


taylor1437 Sat, 05/26/2012 - 09:35
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Dear David,

Thank you so much for your prompt response.

As I found that on RV180, both the One-to-One NAT and the Access Rules are able to specify ALL ports or a specific port, it makes me confuse.

So , did they override each other ? Means if I set One-to-One NAT to forward all ports and set an Access Rules for a specific port to the same public and internal IP, what will it be ? Will it allow all ports forward to this internal IP or just allow the specific port to be forwarded ? Is that not necessary to set One-to-One NAT and Access Rules together for the same IP ?

Best Regards,


davidagu Sun, 05/27/2012 - 16:43
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Hello Taylor,

Typically, you use either port forwarding or one-to-one NAT. One-to-one NAT forwards all ports, while access rules allow you to specify specific ports. Both features can be used to perform the same goal. Acess rules just give you more control.

It is not necessary to use both one-to-one NAT and access rules. Just think of a one-to-one NAT rule as an access rule that forwards all ports. You will use one or the other.

Let us know if you have any other questions.


-David Aguilar

Cisoc Small Business Support Center

taylor1437 Sun, 05/27/2012 - 19:38
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I appreciate you help, thank you so much David !

You make me very clear about that already


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