Lars-Johan Liman works as Sr. Systems Specialist at Netnod Internet Exchange in Stockholm, Sweden. He is responsible for Netnod's root name service for the Domain Name System (DNS), and has spent more than 30 years plumbing and tinkering with the DNS. Over time he has worked with just about every aspect you can imagine – operation, configuration, provisioning, engineering, testing, debugging, documentation, design and evolution, international cooperation and governance, teaching, and even joking with it. He currently serves as chair of ICANN's Customer Standing Committee, and is a member of its Root Server System Advisory Committee, and its Root Server System Governance Working Group.
If you know about DNS, you've probably heard of the Time-to-Live (TTL) field. But mistakes with TTL are more common than you might think. Here we look at the quirks of DNS record sets, parent/child domains and how to avoid TTL problems.
The root name servers are a critical part of the Internet’s infrastructure. Identified by letters A through M, they provide the entry points to the Domain Name System (DNS). Since 2000, Netnod has operated i.root-servers.net, the first root server to be located outside of the United States.