Reconnaissance Techniques — Certified Ethical Hacker (C|EH)

The official ECCOUNCIL documentation our Reconnaissance Techniques practice questions are cited to. Review the primary sources, then practise.

Official references for this objective

Eccouncil — Certified Ethical Hacker (CEH) | #1 Ethical Hacking Certification | EC-Council

NFS Enumeration, SMTP Enumeration, DNS Cache Snooping, DNSSEC Zone Walking, IPsec Enumeration, VoIP Enumeration, RPC Enumeration, Unix/Linux User Enumeration, SMB Enumeration
Eccouncil — What is Ethical Hacking? Complete Guide to Ethical Hackers | EC-Council

without direct contact with the target, making it untraceable.