← Back to Cisco IOS XR Router RTR Security Technical Implementation Guide

V-230043

CAT II (Medium)

The Cisco router must not be configured to use IPv6 Site Local Unicast addresses.

Rule ID

SV-230043r533001_rule

STIG

Cisco IOS XR Router RTR Security Technical Implementation Guide

Version

V3R3

CCIs

CCI-000366

Discussion

As currently defined, site local addresses are ambiguous and can be present in multiple sites. The address itself does not contain any indication of the site to which it belongs. The use of site-local addresses has the potential to adversely affect network security through leaks, ambiguity, and potential misrouting as documented in section 2 of RFC3879. RFC3879 formally deprecates the IPv6 site-local unicast prefix FEC0::/10 as defined in RFC3513.

Check Content

Review the router configuration to ensure FEC0::/10 IPv6 addresses are not defined. 

If IPv6 Site Local Unicast addresses are defined, this is a finding.

Fix Text

Configure the router using only authorized IPv6 addresses.