1. Vietnam National Domain Name Server System
The Vietnam National Domain Name Server System, operated by VNNIC, consists of eight server clusters, including six domestic clusters located in Ha Noi, Ho Chi Minh City, and Da Nang, and two international clusters, with over 100 points of presence (PoPs) across major cities on five continents.
On the map, green markers represent domestic DNS clusters, while purple markers indicate globally distributed clusters.
The system employs advanced technologies such as IPv6, DNSSEC, and Anycast, ensuring that users anywhere in the world can resolve “.vn” domain names quickly and securely over both IPv4 and IPv6, through connection to the nearest authoritative DNS server.
2. Domain Name Query Process
To better understand how the ".vn" domain name resolution mechanism works; let us take the example of querying the domain www.vnnic.vn
Suppose a user wants to access the website with the address www.vnnic.vn
DNS resolution process
Step 1: First, the resolver program on the user’s device sends a request to find the IP address corresponding to the domain name www.vnnic.vn to a DNS resolver server (commonly the DNS servers of ISPs or public DNS servers such as Google DNS, Cloudflare DNS, etc.). The DNS resolver checks its own database (cache) to see if it already contains the IP address information of the requested domain. If it does, the resolver immediately returns the result to the user.
Step 2: If the DNS resolver does not have the record in its cache, it forwards the query to the DNS root servers.
Step 3: The DNS root servers store information about the top-level domain (TLD) name servers, such as .com, .eu, .org, .vn, etc. Since www.vnnic.vn belongs to the "vn" country-code top-level domain (ccTLD), the root servers respond to the resolver with the IP addresses and hostnames of the ".vn" name servers.
Step 4: The DNS resolver then sends a query to the ".vn" name servers to find the IP address for www.vnnic.vn
Step 5: The ".vn" name servers store the delegation information for all domains under ".vn". These servers reply to the DNS resolver with the details (IP addresses and hostnames) of the authoritative DNS servers responsible for the domain vnnic.vn.
Step 6: The DNS resolver then queries the authoritative DNS servers for vnnic.vn to obtain the IP address of www.vnnic.vn
Step 7: Since the authoritative servers for vnnic.vn contains the record for www.vnnic.vn, they return the corresponding IP address to the DNS resolver.
Step 8: The DNS resolver forwards the obtained IP address information to the user’s device.
Step 9: Finally, the user’s device uses this IP address to establish a connection with the web server hosting the www.vnnic.vn website.
