Appendix A System Architecture

MainApp

•Catalyst 6000 MSFC2 with Catalyst software 5.4(3) or later and Cisco IOS 12.1(2)E or later on the MSFC2

•Cisco ASA 5500 series models: ASA 5510, ASA 5520, and ASA 5540

•FWSM

Note The FWSM cannot block in multi-mode admin context.

ACLs and VACLs

If you want to filter packets on an interface or direction that the ARC controls, you can configure the ARC to apply an ACL before any blocks (preblock ACL) and to apply an ACL after any blocks (postblock ACL). These ACLs are configured on the network device as inactive ACLs. You can define preblock and postblock ACLs for each interface and direction. The ARC retrieves and caches the lists and merges them with the blocking ACEs whenever it updates the active ACL on the network device. In most cases, you will want to specify a preexisting ACL as the postblock ACL so that it does not prevent any blocks from taking effect. ACLs work by matching a packet to the first ACE found. If this first ACE permits the packet, a subsequent deny statement will not be found.

You can specify different preblock and postblock ACLs for each interface and direction, or you can reuse the same ACLs for multiple interfaces and directions. If you do not want to maintain a preblock list, you can use the never block option and always block hosts and networks by using existing configuration statements. A forever block is a normal block with a timeout value of -1.

The ARC only modifies ACLs that it owns. It does not modify ACLs that you have defined. The ACLs maintained by ARC have a specific format that should not be used for user-defined ACLs. The naming convention is IPS_<interface_name>_[in out]_[0 1]. <interface_name> corresponds to the name of the blocking interface as given in the ARC configuration.

For Catalyst switches, it is a blocking interface VLAN number. Do not use these names for preblock and postblock ACLs. For Catalyst 6000 VACLs, you can specify a preblock and postblock VACL and only the interface is specified (direction is not used in VLANs). For firewalls, you cannot use preblock or postblock ACLs because the firewall uses a different API for blocking. Instead you must create ACLs directly on the firewalls.

Maintaining State Across Restarts

When the sensor shuts down, the ARC writes all blocks and rate limits (with starting timestamps) to a local file (nac.shun.txt) that is maintained by the ARC. When the ARC starts, this file is used to determine if any block updates should occur at the controlled network devices. Any unexpired blocks found in the file are applied to the network devices at startup. When the ARC shuts down, no special actions on the ACLs are taken even if outstanding blocks are in effect. The nac.shun.txt file is accurate only if the system time is not changed while the ARC is not running.

Caution Do not make manual changes to the nac.shun.txt file.

 

Cisco Intrusion Prevention System Sensor CLI Configuration Guide for IPS 7.2

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Cisco Systems IPS4510K9 manual ACLs and VACLs, Maintaining State Across Restarts, Fwsm
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IPS4510K9 specifications

Cisco Systems has long been a leading player in network security, and its IPS (Intrusion Prevention System) series is a testament to its commitment to safeguarding digital environments. Among its notable offerings are the IPS4510K9 and IPS4520K9 models, both designed to provide advanced threat protection for mid-sized to large enterprise networks.

The Cisco IPS4510K9 and IPS4520K9 are distinguished by their cutting-edge features that help organizations defend against a myriad of cyber threats. These systems utilize a multi-layered approach to security, integrating intrusion prevention, advanced malware protection, and comprehensive visibility across the network.

One of the primary characteristics of the IPS4510K9 is its high performance. It boasts a throughput of up to 1 Gbps, making it suitable for environments that demand rapid data processing and real-time responses to threats. The IPS4520K9, on the other hand, enhances that capability with improved throughput of up to 2 Gbps, accommodating larger enterprises with heavier network traffic. These models are equipped with powerful processors that support complex signature matching and can intelligently distinguish between legitimate traffic and potential threats.

In addition to performance, both models are designed with scalability in mind. They can be easily integrated into existing Cisco infrastructures. This facilitates a seamless enhancement of security without causing significant interruptions to ongoing operations. Moreover, they offer flexible deployment options, allowing organizations to operate them inline or out of band depending on their specific needs.

The Cisco IPS4510K9 and IPS4520K9 leverage advanced detection technologies, utilizing a variety of signature types and heuristic analysis to detect known and unknown threats effectively. They are equipped with real-time alerting and reporting capabilities, giving security teams immediate visibility into potential breaches and enabling them to respond swiftly.

Furthermore, both models support a range of management options through the Cisco Security Manager, allowing for centralized administration, streamlined policy management, and enhanced monitoring capabilities. Automated updates ensure the systems remain current with the latest threat intelligence, vital for staying ahead of evolving cyber threats.

In summary, the Cisco Systems IPS4510K9 and IPS4520K9 represent powerful solutions for organizations seeking robust intrusion prevention capabilities. With their high performance, scalability, and advanced detection technologies, these systems are essential tools in the ever-changing landscape of cybersecurity, providing enterprises with the peace of mind needed to operate securely in today's digital world.
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