Port scanning is an information gathering method that identifies ports and services that are open. Lisa Bock explains how the information may be used as a precursor to an attack, and dissects the ways to protect against scanning such as testing using Nmap, disable or block unnecessary services, and apply the appropriate patches to protect your network.
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- [Voiceover] Port scanning is a popular…information gathering method…that identifies which ports and services are open…and records how they respond to the queries…to gather information on the target.…Because the information may be used…as a precursor to an attack,…effort should be made to prevent port scanning attempts.…Scanning is easy to do and most devices…will experience a scan at some point.…Port scanning has an identifiable signature.…
A firewall or host will respond to a port scan…in one of three ways.…Open and listening.…Open means the host indicates a service…is listening and will respond.…Closed means the host responds…by denying connections to the port,…meaning, "I'm alive, but I'm not talking to you."…No reply.…In this case, the host has filtered, blocked,…or quietly dropped the request and is in stealth mode,…meaning, "If you can't see me, you can't attack me."…Some next generation firewalls…and intrusion prevention systems…use adaptive behavior in that they block ports…if a suspected port scan is in play.…
This course investigates the scanning tools and techniques used to obtain information from a target system, including specially crafted packets, TCP flags, UDP scans, and ping sweeps. Lisa Bock discusses how hackers can identify live systems via protocols, blueprint a network, and perform a vulnerability scan to find weaknesses. She also introduces some of the tools and techniques that hackers use to counter detection via evasion, concealment, and spoofing. In addition, learn how to reduce the threat of tunneling, a method hackers use to circumvent network security.
Note: Our Ethical Hacking series maps to the 18 parts of the EC-Council Certified Ethical Hacker (CEH) exam (312_50). This course maps to the 03 Scanning Networks domain.
- Scanning overview
- Port scanning countermeasures
- Scanning and querying DNS
- Scanning with ICMP
- Mapping (or blueprinting) a network
- Scanning for vulnerabilities
- Using tools such as hping and NetScan
- Evading detection
- Concealing your network traffic
- Preventing tunneling