DNS over IPv6 for Czech Republic Domains (2024-02)

DNS Institute's analysis of Czech Republic government domains (including a small sample of associated infrastructure domains) indicated that around 22% of the domains had an IPv6 mistake related to DNS and 7% completely failed for DNS over IPv6.

On January 17, 2024, the Czech Republic government restarted its transition to IPv6 and DNSSEC compliance plan. This was previously the focus of Government Resolution No. 727, dated June 8, 2009, with the aim to implementing the IPv6 protocol in public administration. Monitoring reports on introducing these technologies is due June 30, 2025 with a status report to be published every year with full transition to IPv6 by May 31, 2027.

This DNS over IPv6 analysis queried 129 IPv6 nameservers (including the top levels). Of the 212 Czech domains in the DNS Institute analysis:

7% completely failed for DNS over IPv6.
9% had a NS nameserver that didn't have an IPv6 address.
17% had a delegated NS nameserver that didn't have an IPv6 address.
2 had a nameserver timeout over UDP and unreachable over TCP.
7% had only one delegated nameserver that answered.
7% had a nameserver that returned Extended Error #18 Prohibited (from seven nameservers).
4 had NS records that didn't match its parent's delegated NS records.
60% didn't have nameservers in at least two topologically-separate networks.
77% didn't have nameservers in at least two separate Autonomous System (AS) Originations.

The domains that completely failed include army.cz (it has a NS with AAAA that works, but that isn't in the parent delegations!), avu.cz, ceskatelevize.cz, chemtk.cz, ct24.cz, damu.cz, hamu.cz, kcict.cz, mzcr.cz, nzip.cz, senat.cz, techlib.cz, uochb.cz, and uzis.cz.

DNS Institute performs comprehensive DNS and DNSSEC analysis, security testing, and commercial monitoring of nameservers and domains for S&P Global Top 100 Banks, Fortune 500 companies, national governments, and various TLDs based on IETF RFC specifications and best practices, government requirements, and registry guidelines. Past overviews of DNS over IPv6 include: India, Fortune 500, and U.S. government.