The system must set strict multihoming.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-216375SRG-OS-000480SOL-11.1-050080SV-216375r959010_rule2024-11-253
Description
These settings control whether a packet arriving on a non-forwarding interface can be accepted for an IP address that is not explicitly configured on that interface. This rule is NA for documented systems that have interfaces that cross strict networking domains (for example, a firewall, a router, or a VPN node).
ℹ️ Check
Determine if strict multihoming is configured. # ipadm show-prop -p _strict_dst_multihoming -co current ipv4 # ipadm show-prop -p _strict_dst_multihoming -co current ipv6 If the output of all commands is not "1", this is a finding.
✔️ Fix
The Network Management profile is required. Disable strict multihoming for IPv4 and IPv6. # pfexec ipadm set-prop -p _strict_dst_multihoming=1 ipv4 # pfexec ipadm set-prop -p _strict_dst_multihoming=1 ipv6