Feature History for Twice NAT

Chapter 5 Configuring Twice NAT (ASA 8.3 and Later)

Table 5-1lists each feature change and the platform release in which it was implemented. ASDM is backwards-compatible with multiple platform releases, so the specific ASDM release in which support was added is not listed.

Table 5-1	Feature History for Twice NAT

		Platform
Feature Name		Releases	Feature Information

Twice NAT		8.3(1)	Twice NAT lets you identify both the source and destination
			address in a single rule.
			We modified the following screen: Configuration > Firewall
			> NAT Rules.

Identity NAT configurable proxy ARP and route		8.4(2)/8.5(1)	In earlier releases for identity NAT, proxy ARP was
lookup			disabled, and a route lookup was always used to determine
			the egress interface. You could not configure these settings.
			In 8.4(2) and later, the default behavior for identity NAT
			was changed to match the behavior of other static NAT
			configurations: proxy ARP is enabled, and the NAT
			configuration determines the egress interface (if specified)
			by default. You can leave these settings as is, or you can
			enable or disable them discretely. Note that you can now
			also disable proxy ARP for regular static NAT.
			For pre-8.3 configurations, the migration of NAT exempt
			rules (the nat 0 access-listcommand) to 8.4(2) and later
			now includes the following keywords to disable proxy ARP
			and to use a route lookup: no-proxy-arpand route-lookup.
			The unidirectional keyword that was used for migrating to
			8.3(2) and 8.4(1) is no longer used for migration. When
			upgrading to 8.4(2) from 8.3(1), 8.3(2), and 8.4(1), all
			identity NAT configurations will now include the
			no-proxy-arp and route-lookup keywords, to maintain
			existing functionality. The unidirectional keyword is
			removed.
			We modified the following screen: Configuration > Firewall
			> NAT Rules > Add/Edit NAT Rule

PAT pool and round robin address assignment		8.4(2)/8.5(1)	You can now specify a pool of PAT addresses instead of a
			single address. You can also optionally enable round-robin
			assignment of PAT addresses instead of first using all ports
			on a PAT address before using the next address in the pool.
			These features help prevent a large number of connections
			from a single PAT address from appearing to be part of a
			DoS attack and makes configuration of large numbers of
			PAT addresses easy.
			We modified the following screens: Configuration >
			Firewall > NAT Rules > Add/Edit NAT Rule.

Cisco ASA Series Firewall ASDM Configuration Guide

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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.

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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 Feature History for Twice NAT

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

Platform

Feature Name

Releases

Feature Information

no-proxy-arp and route-lookup keywords, to maintain

Cisco ASA Series Firewall ASDM Configuration Guide

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