On Cisco Routers, the designation uses the commands ip nat outside and ip nat inside:Īll address translation commands are preceded with these two words. Instead, they must be explicitly told which of their interface(s) are acting as the Outside and which interface(s) are acting as the Inside. Routers however, cannot see the entire network topology. It is easy to look at a network topology diagram to determine which interfaces are facing the Internet and which interfaces are facing the internal servers. The first step to configuring NAT on any Cisco IOS router is designating which interfaces should be considered “ Inside” and which should be considered “ Outside”. Designating Inside and Outside interfacesĭesignating Inside and Outside interfaces.In addition, since the configuration below applies to Cisco routers, we will be using Cisco NAT terminology to reference IP addresses (and/or ports) involved in the translation.
#Learning cisco ios series
It is highly recommended to read each article in the NAT article series before attempting to configure NAT using this guide. We will look at the Cisco NAT configuration commands and explore the syntax for each of these types of address translation. There are only four types of network address translation: Static NAT, Static PAT, Dynamic PAT, Dynamic NAT. This is a follow up article to the Network Address Translation article series which thoroughly covered the operation of NAT and answers the questions “ What is NAT?” and “ How does NAT work?“. In this article, we will illustrate the Cisco NAT configuration on IOS Routers.