There is a current effort to fully transition the US government internal networks to IPv6 only: https://www.gsa.gov/technology/technology-products-services/it-s

There is a current effort to fully transition the US government internal networks to IPv6 only: https://www.gsa.gov/technology/technology-products-services/it-security/internet-protocol-version-6-ipv6 https://www.gsa.gov/technology/technology-products-services/... Considering how many old, IPv4 based management and security tools are probably in use, it will be an exciting time.