Can Blocking Root DNS Servers Erase a Country from the Internet? A Technical Deep Dive

The ongoing Russia‑Ukraine war also has a digital front, prompting the question: if the United States were to sanction Russia’s Internet by blocking the root DNS servers, could Russia vanish from the Internet?

To answer this, we first need to understand basic Internet operations. Users access services through client software (e.g., browsers, apps) that communicate with servers identified by IP addresses. Because numeric IPs are hard to remember, humans use domain names, which are translated to IPs by the Domain Name System (DNS).

DNS is a hierarchical system consisting of local DNS servers, authoritative name servers, top‑level domain (TLD) servers, and root name servers.

Local DNS server Authoritative name server Top‑level domain server Root name server

When a computer needs to resolve a domain like www.example.com, it queries its local DNS (LDNS). If the LDNS lacks the answer, it asks a root server, which directs it to the appropriate TLD server, which then points to the authoritative server that finally returns the IP address.

There are only 13 root DNS servers worldwide (10 in the US, 1 each in the UK, Sweden, and Japan). Their names range from A.root-servers.net to M.root-servers.net, with A being the primary root and the others as secondary roots.

Although there are only 13 logical root servers, each has many physical mirror nodes; as of February 2022 there were 1,518 physical instances distributed globally. This massive replication is achieved through anycast, allowing multiple machines to share the same IP address.

In China, numerous root‑server mirrors exist—Beijing alone hosts eight nodes—so domestic DNS queries are typically answered by local mirrors rather than the overseas roots.

All secondary roots synchronize data from the primary root, and each mirror synchronizes from its corresponding root server. Consequently, if the US were to delete all .cn records from the primary root, the change would propagate to all mirrors, potentially affecting global resolution of Chinese domains.

However, because domestic queries are handled by local mirrors, a country that maintains its own root‑server mirrors could resist such deletions. The mirrors could simply refuse to apply the US‑issued changes, ensuring that users within the country continue to resolve local domains.

Russia has taken similar steps by deploying its own root mirrors, allowing it to reject deletions of .ru records.

Therefore, simply blocking or tampering with the 13 logical root DNS servers would not make a nation disappear from the Internet, especially if that nation operates its own mirrored infrastructure.

For a full list of root server names and IPs, see https://www.internic.net/domain/named.root. For a global view of root‑server locations, see https://root-servers.org/.