Mark works as a Network Administrator for Perfect Inc. The company has both wired and wireless networks. An attacker attempts to keep legitimate users from accessing services that they require. Mark…

An internal attack describes the origin of a threat (from within the organization), not the attacker's method or goal of disrupting service availability.

A reconnaissance attack involves passively or actively gathering information about a target network, not actively blocking user access to services.

A Land attack is a specific exploit that sends a packet with identical source and destination IP addresses to crash or freeze a system, not a general category describing service denial.

A Denial of Service attack is specifically aimed at overwhelming or blocking access to services so that legitimate users cannot use them. The deployment of IDS/IPS sensors to detect and mitigate the attack is a standard defensive response to DoS threats. The attacker's stated goal - keeping users from services they require - is the textbook definition of a DoS attack.