What happens when telcos’ DNS server is down

Mumbai: Internet users across India started reporting outages on their networks on June 18, reaching over 45,000 complaints by market leader Reliance Jio users. On June 19, a similar downtime was reported by second-largest telco Bharti Airtel’s users complaining against lost networks 9,000 times. Resultantly, applications like WhatsApp, Facebook, Telegram, Amazon and many others also started seeing a surge in complaints. The issue at hand was that the telcos’ DNS (domain name system) server was down which meant that it was unable to return IP addresses. ET explains the problem along with data on the outages.