CCNP Security IPS 642-627 Official Cert Guide: Network IPS Traffic Analysis Methods, Evasion Possibilities, and Anti-evasive Countermeasures

Article Description

This chapter covers the various methods used for traffic analysis using a network IPS sensor, the various evasion techniques used by attackers to bypass detection & filtering while understanding the benefits and limitations of each method to assess the risk of evasion, and the various countermeasures, tools, and choosing the best approach based on the methods used by attackers.

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CCNP Security IPS 642-627 Official Cert Guide

CCNP Security IPS 642-627 Official Cert Guide

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Definitions of Key Terms

Definitions of Key Terms

Define the following key terms from this chapter, and check your answers in the glossary.

  • de-obfuscation: the practice that is used to simplify something such as code that was intentionally made more difficult to understand to evade detection.
  • evasion: the act or instance of avoiding escaping, or shirking something. .
  • encode: the process by which information/code from a source is converted to another code to be communicated to a particular receiver or host.
  • decode: the process by which information/code is converted back into information understandable by the receiver or host.
  • reconnaissance attack: a common method by which a user or users maliciously gather information about a target network or system to be used for subsequent access or denial of service attacks.
  • SSL: Also known as Secure Socket Layer is commonly-used protocol for managing the security of a message transmission on the Internet. SSL has been succeeded by Transport Layer Security, which is based on SSL thus when SSL is used in text it's assumed TLS/SSL is being used. SSL uses a program layer between Hypertext Transfer Protocol (HTTP) and Transport Control Protocol (TCP) layers.
  • IPSec: Also known as Internet Protocol Security provides a method of authentication and encryption for each IP packet of a communications session. IPSec leverages protocols such as AH (Authentication Headers) for integrity and authentication; ESP (Encapsulating Security Payloads) for confidentiality, authentication, integrity, and anti-replay; and ISAKMP (Internet Security Association and Key Management Protocol) for a framework for authentication and key exchange.
  • VPN: Also known as Virtual Private Network which is a method of communicating securely using IPSec, SSL/TLS, etc. over a public or shared telecommunications infrastructure.
  • GRE: Also known as Generic Routing Encapsulation which is a tunneling protocol developed by Cisco Systems that can encapsulate a wide variety of network layer protocol packet types inside IP tunnels.