NAT Example Routed Mode | Cisco Systems ASA 5580, ASA 5505 manual

Chapter 6 Configuring NAT (ASA 8.2 and Earlier)

NAT Overview

general operations configuration guide for more information about security levels. See the “NAT Control” section on page 6-4for more information about NAT control.

Note In this document, all types of translation are referred to as NAT. When describing NAT, the terms inside and outside represent the security relationship between any two interfaces. The higher security level is inside and the lower security level is outside. For example, interface 1 is at 60 and interface 2 is at 50; therefore, interface 1 is “inside” and interface 2 is “outside.”

Some of the benefits of NAT are as follows:

•You can use private addresses on your inside networks. Private addresses are not routable on the Internet.

•NAT hides the real addresses from other networks, so attackers cannot learn the real address of a host.

•You can resolve IP routing problems such as overlapping addresses.

See Table 10-1 on page 10-4for information about protocols that do not support NAT.

NAT in Routed Mode

Figure 6-1shows a typical NAT example in routed mode, with a private network on the inside. When the inside host at 10.1.1.27 sends a packet to a web server, the real source address, 10.1.1.27, of the packet is changed to a mapped address, 209.165.201.10. When the server responds, it sends the response to the mapped address, 209.165.201.10, and the security appliance receives the packet. The security appliance then changes the translation of the mapped address, 209.165.201.10 back to the real address, 10.1.1.1.27 before sending it to the host.

Figure 6-1 NAT Example: Routed Mode

Originating

Packet

Translation

10.1.2.27209.165.201.10

Web Server

www.cisco.com

Outside

209.165.201.2

Security

Appliance

10.1.2.1

Inside

10.1.2.27

Responding

Packet

Undo Translation

209.165.201.10 10.1.2.27

130023

Cisco ASA Series Firewall ASDM Configuration Guide

6-2

ASA Services Module, ASA 5555-X, ASA 5545-X, ASA 5585-X, ASA 5580 specifications

Cisco Systems has long been a leader in the field of network security, and its Adaptive Security Appliance (ASA) series is a testament to this expertise. Within the ASA lineup, models such as the ASA 5505, ASA 5580, ASA 5585-X, ASA 5545-X, and ASA 5555-X stand out for their unique features, capabilities, and technological advancements.

The Cisco ASA 5505 is designed for small businesses or branch offices. It provides essential security features such as firewall protection, flexible VPN capabilities, and intrusion prevention. The ASA 5505 supports a user-friendly interface, allowing for straightforward management. Its built-in threat detection and prevention tools provide a layered defense, and with scalability in mind, it can accommodate various expansion options as organizational needs grow.

Moving up the line, the ASA 5580 delivers greater throughput and advanced security features. This model is suited for medium to large enterprises that require robust protection against increasingly sophisticated threats. Its multi-core architecture allows it to manage high volumes of traffic seamlessly while maintaining excellent performance levels. The ASA 5580 also supports application-layer security and customizable access policies, making it highly adaptable to diverse security environments.

The ASA 5585-X further enhances Cisco's security offerings with advanced malware protection and extensive security intelligence capabilities. It incorporates next-generation firewall features, including context-aware security, and supports advanced threat detection technologies. This model is ideal for large enterprises or data centers that prioritize security while ensuring uninterrupted network performance and availability.

For enterprises requiring a balance of performance and security, the ASA 5545-X presents a compelling option. This model features scalable performance metrics, high availability, and integrated advanced threat protection. Coupled with advanced endpoint protection and detailed monitoring capabilities, the ASA 5545-X enables organizations to manage their security posture effectively.

Lastly, the ASA 5555-X blends cutting-edge technologies with strong security infrastructures. It boasts high throughput and the ability to execute deep packet inspections. Its sophisticated architecture supports threat intelligence feeds that provide real-time security updates, making it a powerful tool against modern threats.

Each of these Cisco ASA models brings specific advantages to varied environments. Their integrative capabilities enable businesses to enhance their security postures while benefiting from seamless scalability and management. As cybersecurity threats evolve, these advanced appliances play a vital role in protecting valuable digital assets.

Cisco Systems ASA 5580, ASA 5505, ASA 5545-X, ASA 5555-X, ASA 5585-X manual NAT Example Routed Mode

Models: ASA Services Module ASA 5555-X ASA 5545-X ASA 5585-X ASA 5580 ASA 5505