Chapter 26 Configuring the Botnet Traffic Filter

Configuring the Botnet Traffic Filter

When an address matches, the ASA sends a syslog message. The only additional action currently available is to drop the connection.

Prerequisites

In multiple context mode, perform this procedure in the context execution space.

Recommended Configuration

Although DNS snooping is not required, we recommend configuring DNS snooping for maximum use of the Botnet Traffic Filter (see the “Enabling DNS Snooping” section on page 26-9). Without DNS snooping for the dynamic database, the Botnet Traffic Filter uses only the static database entries, plus any IP addresses in the dynamic database; domain names in the dynamic database are not used.

We recommend enabling the Botnet Traffic Filter on all traffic on the Internet-facing interface, and enabling dropping of traffic with a severity of moderate and higher.

Detailed Steps

Step 1 Choose the Configuration > Firewall > Botnet Traffic Filter > Traffic Settings pane. Step 2 To enable the Botnet Traffic Filter on specified traffic, perform the following steps:

a.In the Traffic Classification area, check the Traffic Classified check box for each interface on which you want to enable the Botnet Traffic Filter.

You can configure a global classification that applies to all interfaces by checking the Traffic Classified check box for Global (All Interfaces). If you configure an interface-specific classification, the settings for that interface overrides the global setting.

b.For each interface, from the ACL Used drop-down list choose either --ALL TRAFFIC-- (the default), or any ACL configured on the ASA.

For example, you might want to monitor all port 80 traffic on the outside interface.

To add or edit ACLs, click Manage ACL to bring up the ACL Manager. See the “Adding ACLs and ACEs” section on page 21-2in the general operations configuration guide for more information.

Step 3 (Optional) To treat greylisted traffic as blacklisted traffic for action purposes, in the Ambiguous Traffic Handling area, check the Treat ambiguous (greylisted) traffic as malicious (blacklisted) traffic check box.

If you do not enable this option, greylisted traffic will not be dropped if you configure a rule in the Blacklisted Traffic Actions area. See the “Botnet Traffic Filter Address Types” section on page 26-2for more information about the greylist.

Step 4 (Optional) To automatically drop malware traffic, perform the following steps.

To manually drop traffic, see the “Blocking Botnet Traffic Manually” section on page 26-12.

a.In the Blacklisted Traffic Actions area, click Add.

The Add Blacklisted Traffic Action dialog box appears.

b.From the Interface drop-down list, choose the interface on which you want to drop traffic. Only interfaces on which you enabled Botnet Traffic Filter traffic classification are available.

c.In the Threat Level area, choose one of the following options to drop traffic specific threat levels. The default level is a range between Moderate and Very High.

Cisco ASA Series Firewall ASDM Configuration Guide

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Cisco Systems ASA 5545-X, ASA 5505, ASA 5555-X, ASA 5585-X, ASA 5580, ASA Services Module Recommended Configuration, 26-11

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.