Which type of attack is directed against the network directly:

A.
Denial of Service

B.
phishing

C.
trojan horse

D.
…

Explanation:
BD
Denial of service refers to willful attempts to disrupt legitimate users from getting access to the resources they
intend to. Although no complete solution exists, administrators can do specific things to protect the network
from a DoS attack and to lessen its effects and prevent a would-be attacker from using a system as a source
of an attack directed at other systems. These mitigation techniques include filtering based on bogus source IP
addresses trying to come into the networks and vice versa. Unicast reverse path verification is one way to
assist with this, as are access lists. Unicast reverse path verification looks at the source IP address as it comes
into an interface, and then looks at the routing table. If the source address seen would not be reachable out of
the same interface it is coming in on, the packet is considered bad, potentially spoofed, and is dropped.
Source: Cisco Official Certification Guide, Best Practices Common to Both IPv4 and IPv6, p.332