Final answer:
IP Source Guard is a network security feature that protects against IP spoofing by filtering traffic based on known IP address and MAC address bindings.
It does not protect directly against DDoS attacks, DNS vulnerabilities, or unauthorized VPN access.
Step-by-step explanation:
IP Source Guard is a feature used in network switches that provides security by filtering traffic based on the DHCP snooping binding database and/or manually configured IP source bindings.
This security feature protects against IP spoofing, where an attacker could try to impersonate another device by using a forged source IP address in their packets.
When IP Source Guard is enabled on a switch port, only traffic that matches the known IP address and MAC address binding is allowed through the port, effectively preventing nefarious individuals from using an IP address that does not belong to them to conduct malicious activities.
This feature does not directly protect against DDoS attacks, DNS vulnerabilities, or unauthorized VPN access, although it can be a component of an overall network security strategy that mitigates various types of attacks.