Why 13 DNS Root Servers Keep the Internet Running – Explained

What is a DNS root server?

Root servers, also known as DNS root servers, are name servers that form the first step in resolving any domain name, converting domain names to IP addresses.

The root zone is a global list of top‑level domains (TLDs) including generic TLDs (.com, .net, .org), country‑code TLDs (.uk, .cn) and internationalized TLDs, maintained by IANA, part of ICANN.

Domain‑to‑IP mapping is performed hierarchically; root servers serve the root zone, which publishes the root zone file containing resource records for all TLD authoritative name servers. They operate in two ways:

Directly answer queries for records in the root zone.

Refer the query to the appropriate TLD name server.

How do root servers work?

The resolution process works as follows:

When a user types a URL, the request first goes to the local ISP’s DNS resolver, which may have a cached answer.

If not cached, the resolver queries the root server, which does not know the specific IP but knows which TLD server (.com, .net, etc.) is authoritative.

The root server returns a list of TLD servers.

The TLD server returns the authoritative name server for the requested domain.

The authoritative server finally returns the IP address, which the resolver caches and returns to the client.

How many root DNS servers are there?

There are 13 logical root server identities, each represented by multiple physical servers distributed worldwide.

Why only 13 root servers?

The original design limited the root zone to 13 entries because of IPv4 packet size constraints (512‑byte limit) and the need to fit the root zone data within that space.

Each of the 13 IP addresses now maps to a cluster of servers using anycast routing, providing redundancy and resilience against attacks.

Where are the root DNS servers located?

They are distributed globally; diagrams illustrate their locations.

China’s DNS situation

China does not host any of the 13 original root server identities, but it operates many regional DNS nodes (26 listed) and participates in the IPv6 root server ecosystem with four servers (one primary, three secondary).

Public DNS server addresses (common)

Preferred: 114.114.114.114
Backup: 114.114.115.115

Preferred: 223.5.5.5
Backup: 223.6.6.6

IPv4: 180.76.76.76
IPv6: 2400:da00::6666

Preferred: 119.29.29.29
Backup: 119.28.28.28
Backup: 182.254.118.118
Backup: 182.254.116.116

Preferred: 1.2.4.8
Backup: 210.2.4.8

2001:da8:200:ffff::28
2001:da8:8000:1:202:120:2:101

2001:da8:202:10::36
or
2001:da8:202:10::37

Conclusion

DNS underpins almost every Internet service, and root DNS servers are a cornerstone of the global network. Understanding the 13 root servers and the broader DNS ecosystem helps appreciate the resilience and security challenges of modern networking.