SHANGHAI, China – 3 September 2019 – The Internet Corporation for Assigned Names and Numbers (ICANN) today announced the successful installation of an ICANN Managed Root Server (IMRS) instance in Shanghai, China.
A root server is a name server for the Domain Name System (DNS) root zone. Root servers respond to DNS lookup requests made by DNS resolvers generally operated by Internet service providers. When the request is a query about the root zone itself, the root server will respond authoritatively with the answer. For all other queries, the root server will respond with either a referral to the appropriate top-level domain (TLD) name server or an error response (e.g. to indicate a non-existent TLD). Each root server is made up of a number of machines at multiple locations. These machines are known as instances.
An instance makes use of an Internet traffic routing technique known as "anycast" that allows all the root server's instances to have the same two IP addresses (an IPv4 address and an IPv6 address) and to serve the same DNS content, including information about the name servers for TLDs. Increasing the number of instances improves the overall fault tolerance of the DNS, bolsters the resilience against certain types of cyber threats such as Denial of Service (DoS) attacks, and can reduce the response time that local Internet users experience during DNS queries.
The installation of the Shanghai instance is a joint activity between ICANN, China Internet Network Information Center (CNNIC), and the local community. Shanghai Telecom supplied the equipment necessary for the installation and the bandwidth needed to support the instance.
"We appreciate CNNIC's efforts to host this IMRS instance. This commitment improves root zone DNS service, and augments the technical stability and resiliency of the DNS in the region," said David Conrad, ICANN Chief Technology Officer.
Contrary to common misconception, root servers do not control the Internet. The operation of an instance also does not provide any mechanism to alter content of the DNS. Any modification of root zone content will be mitigated by a part of the DNS protocol known as the DNS Security Extensions (DNSSEC) and if an instance fail to respond to a query, resolvers will ask the same question to another instance or root server.
Regardless of which root server the resolvers are sending queries to, spreading more instances geographically leads to a more resilient, dispersed system that reduces the risk of Internet users being taken offline by a problem or attack. The increased distribution of instances also ensures that the turnaround time of a DNS query and response is as fast as possible, resulting in better experiences for Internet users.
The root name server system is comprised of over 1,000 instances operated by 12 independent organizations, including ICANN. Currently, ICANN manages more than 165 IMRS instances located all over the world, where most of which are hosted by third parties.
This is the third IMRS instance installed in China, and the first one located in eastern China. The other two instances are located in Beijing.
For more information about IMRS, please visit www.dns.icann.org/.
For more information about the global root server system, please visit www.root-servers.org.
ICANN's mission is to help ensure a stable, secure, and unified global Internet. To reach another person on the Internet, you have to type an address – a name or a number – into your computer or other device. That address must be unique, so computers know where to find each other. ICANN helps coordinate and support these unique identifiers across the world. ICANN was formed in 1998 as a not-for-profit public-benefit corporation and a community with participants from all over the world.