Embedded Files
Introduction
Introduction
DNS services operate quietly, behind the scenes, translating user-friendly domain names into IP addresses for web-browsers across the world. Supporting services like our own websites, emails, and MUCH more.
In this post, we'll explore the world of DNS TTL, offer some generalisations, and an optimisation or two. Hopefully to help you enjoy a speedier internet experience, or your clients to observe a stable website/email service you own.
Date: 2008-01-04
Author: Simon Jackson
Understanding DNS TTL:
Understanding DNS TTL:
Time to Live (TTL) represents a recommended cache-lifetime, for DNS records, dictating how long this information remains cached by resolvers and other DNS servers, typically measured in seconds. When you visit a website, your device's DNS resolver stores the IP address associated with the domain name. TTL determines how long this IP address remains valid without the need for re-querying the authoritative DNS server.
Improvements and Generalisations:
Improvements and Generalisations:
Seeing TTL in action
Seeing TTL in action
Observations
Observations
There are two answers received with the above DNS query.
First.. blog. This is the CNAME value. and rightly so that returns a TTL of 1 hour. To reduce the number of DNS queries, 1 hour is a reasonable metric. Although we could increase this to 24 hours; but it's not essential.
Second... ghs.googlehosted.com A record.. this has a TTL of 5 mintes! Likely because there is some form of traffic load balancer on the outside, with a datacentre failover mechanism that updates DNS, so clients should recover after 5 minutes.
Conclusion
Conclusion
By optimising DNS TTL and making well-informed decisions regarding TTL values, you can significantly enhance your website's speed and reliability. Tailoring these strategies to your website's specific requirements, implementing best practices, and exploring advanced optimisations will enable you to deliver a swifter and more responsive online experience. Remember, in the realm of DNS, every second counts!
Page updated
Report abuse