A Network Administrator Is Responding to a Help Desk Ticket

Multiple Choice

A network administrator is responding to a help desk ticket, which states an unknown wireless access point is broadcasting in a specific area. Upon investigation, the administrator finds that a user brought a wireless access point from home and plugged it into the corporate network. This resulted in an attacker using the unsecured wireless LAN to gain access to the network. Which of the following should the network administrator have done to BEST prevent this problem?

A) Changed the default credentials on the network switches
B) Installed a Layer 7 firewall
C) Implemented port security
D) Disabled unnecessary services on the network switches