Describes how NAT conserves IP addresses by translating private addresses to globally routable addresses and can provide external access to internal servers while hiding internal addresses.
Network address translations
This topic explains how network address translation (NAT) conserves IP addresses by translating private addresses into global routable addresses.
Limitations of network address translation
Use these guidelines when configuring NAT to understand hardware, protocol, and feature limitations that may impact translation, session handling, protocol support, and feature compatibility on your device.
NAT configuration recommendations and types
This topic explains best practices and recommendations for configuring NAT, including address overlap avoidance, ACL filtering, address pool usage, and interface selection to ensure optimal NAT operation and prevent undesired behavior.
How network address translation works
Network address translation (NAT) converts local addresses to global addresses for outbound traffic and global addresses to local addresses for inbound traffic.
NAT types and addresses
Defines NAT inside and outside local and global addresses, and describes the translation and entry types used for bidirectional address translation.
NAT Port Address Translation
This topic explains how Port Address Translation (PAT), also known as NAT overloading, allows multiple local addresses to share a single global IP address by using port numbers as differentiators, thereby conserving the global address pool efficiently.
NAT for overlapping networks
Describes how NAT translates source and destination addresses to enable connectivity between networks that use identical or conflicting IP address ranges.
VRF-aware NAT
This topic explains how VRF-aware NAT enables address and port translation by considering the VRF context of private networks, allowing NAT to function in environments with overlapping address spaces and multiple VRFs.
Route map-based NAT
Explains how route maps define match criteria and actions for static or dynamic NAT including destination-based translations that map the same local address to different global addresses.
Address-only translation
This topic explains Address Only Translation (AOT), a NAT optimization mechanism that translates only IP address fields, optimizes hardware resource usage, and enables line-rate forwarding of more flows than traditional NAT.
Application-Level Gateways with NAT
This topic explains how NAT Application-Level Gateways (ALGs) enable applications that carry address and port information in their payloads to function correctly across NAT domains.
Configure NAT external IP addresses
Learn how to configure NAT so that only the external IP address is translated, disabling translation of embedded addresses in packet payloads when required.
Configure NAT on a Layer 3 port channel
Learn how to configure Network Address Translation (NAT) on a Layer 3 port channel by assigning IP addresses and specifying inside and outside NAT interfaces on your switch.
Configure NAT timeouts
Learn how to configure address translation timeouts for NAT, including default values and how to adjust them for TCP, UDP, ICMP, and other flows on your device.
Network address translation commands
This topic explains how to troubleshoot and verify Network Address Translation (NAT) configuration using various show and debug commands.
Feature history for network address translation
Feature history for network address translation.