Details

The network device must block IPv6 Unique Local Unicast Addresses on the enclaves perimeter ingress and egress filter.

The IANA has assigned the FC00–/7 prefix to Unique Local Unicast addresses. Unique Local Address (ULA) is a routable address that is not intended to be on the Internet. Site border routers and firewalls should be configured to block any packets with ULA source or destination addresses outside of the site. This will ensure that packets with Local IPv6 destination addresses will not be forwarded outside of the site via a default route. Drop all inbound IPv6 packets with an address FC00–/7 as its source address. Note that includes any address beginning with FC or FD.

NOTE: Change ‘IPV6_INGRESS_ACL’ to the access control list for IPv6 inbound connection filtering.

Solution

The administrator will configure the router ACLs to restrict IP addresses that contain any Unique Local Unicast addresses.

Supportive Information

The following resource is also helpful.

• https://iasecontent.disa.mil/stigs/zip/U_Network_Perimeter_Router_L3_Switch_V8R32_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Cisco.

References

• 800-53|SC-7(11)
• CAT|II
• Rule-ID|SV-15420r2_rule
• STIG-ID|NET-IPV6-032
• Vuln-ID|V-14703

Source

• Tenable.com/audits