22-10

Chapter 22 Configuring Connection Settings

Configuring Connection Settings

Table 22-1 tcp-map Commands (continued)

Command	Notes

synack-data {allow drop}	Sets the action for TCP SYNACK packets that contain data.
	The allow keyword allows TCP SYNACK packets that contain
	data.
	(Default) The drop keyword drops TCP SYNACK packets that
	contain data.

syn-data {allow drop}	Sets the action for SYN packets with data.
	(Default) The allow keyword allows SYN packets with data.
	The drop keyword drops SYN packets with data.

tcp-options {selective-ack	Sets the action for packets with TCP options, including the
timestamp window-scale}	selective-ack, timestamp, or window-scale TCP options.
{allow clear}	(Default) The allow keyword allows packets with the specified

Or	option.
tcp-options range lower upper	(Default for range) The clear keyword clears the option and
{allow clear drop}	allows the packet.
	The drop keyword drops the packet with the specified option.
	The selective-ackkeyword sets the action for the SACK option.
	The timestamp keyword sets the action for the timestamp option.
	Clearing the timestamp option disables PAWS and RTT.
	The widow-scalekeyword sets the action for the window scale
	mechanism option.
	The range keyword specifies a range of options. The lower
	argument sets the lower end of the range as 6, 7, or 9 through 255.
	The upper argument sets the upper end of the range as 6, 7, or 9
	through 255.

ttl-evasion-protection	Disables the TTL evasion protection. Do not enter this command
	it you want to prevent attacks that attempt to evade security policy.
	For example, an attacker can send a packet that passes policy with
	a very short TTL. When the TTL goes to zero, a router between the
	ASA and the endpoint drops the packet. It is at this point that the
	attacker can send a malicious packet with a long TTL that appears
	to the ASA to be a retransmission and is passed. To the endpoint
	host, however, it is the first packet that has been received by the
	attacker. In this case, an attacker is able to succeed without
	security preventing the attack.

Cisco ASA Series Firewall CLI Configuration Guide

ASA 5555-X, and the ASA Services Module, 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.

Chapter 22 Configuring Connection Settings

Command

synack-data {allow drop}

syn-data {allow drop}

{allow clear drop}

ttl-evasion-protection

22-10

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