A security administrator is notified that users attached to a particular switch are having intermittent connectivity issues. Upon further research, the administrator finds evidence of an ARP spoofing attack. Which of the following could be utilized to provide protection from this type of attack?
A. Configure MAC filtering on the switch. B. Configure loop protection on the switch. C. Configure flood guards on the switch. D. Configure 802.1x authentication on the switch.
Answer: C
Explanation: ARP spoofing is a type of attack in which a malicious actor sends falsified ARP (Address Resolution Protocol) messages over a local area network. This results in the linking of an attacker’s MAC address with the IP address of a legitimate computer or server on the network. Once the attacker’s MAC address is connected to an authentic IP address, the attacker will begin receiving any data that is intended for that IP address. ARP spoofing can enable malicious parties to intercept, modify or even stop data in-transit. ARP spoofing attacks can only occur on local area networks that utilize the Address Resolution Protocol. To perform ARP spoofing the attacker floods the network with spoofed ARP packets. As other hosts on the LAN cache the spoofed ARP packets, data that those hosts send to the victim will go to the attacker instead. From here, the attacker can steal data or launch a more sophisticated follow-up attack.
A flood guard configured on the network switch will block the flood of spoofed ARP packets.
At an organization, unauthorized users have been accessing network resources via unused network wall jacks. Which of the following would be used to stop unauthorized access?
A. Configure an access list. B. Configure spanning tree protocol. C. Configure port security. D. Configure loop protection.
Answer: C
Explanation: Port security in IT can mean several things. It can mean the physical control of all connection points, such as RJ-45 wall jacks or device ports, so that no unauthorized users or unauthorized devices can attempt to connect into an open port. This can be accomplished by locking down the wiring closet and server vaults and then disconnecting the workstation run from the patch panel (or punch-down block) that leads to a room’s wall jack. Any unneeded or unused wall jacks can (and should) be physically disabled in this manner. Another option is to use a smart patch panel that can monitor the MAC address of any device connected to each and every wall port across a building and detect not just when a new device is connected to an empty port, but also when a valid device is disconnected or replaced by an invalid device.