The layer 2 switch must have IP Source Guard enabled on all user-facing or untrusted access switch ports.
Overview
Finding ID
Version
Rule ID
IA Controls
Severity
V-206659
SRG-NET-000362-L2S-000026
SV-206659r856589_rule
Medium
Description
IP Source Guard provides source IP address filtering on a Layer 2 port to prevent a malicious host from impersonating a legitimate host by assuming the legitimate host's IP address. The feature uses dynamic DHCP snooping and static IP source binding to match IP addresses to hosts on untrusted Layer 2 access ports. Initially, all IP traffic on the protected port is blocked except for DHCP packets. After a client receives an IP address from the DHCP server, or after static IP source binding is configured by the administrator, all traffic with that IP source address is permitted from that client. Traffic from other hosts is denied. This filtering limits a host's ability to attack the network by claiming a neighbor host's IP address.