How to Check TTL DNSby Mark Robinson
The Domain Name System serves as the "telephone book" of the Internet. It translates the numerical IP addresses of websites into the domain names recognized and used by browsers. If the user has problems with accessing the most current versions of their website or if the site is resolving to its old IP address, the "nslookup" command can be used as a troubleshooting tool to determine the domain's "time-to-live" value. This information can be used towards resolving these and other issues.
Click the "Start" icon on the task bar. Enter "cmd" into the search bar within the "Start" menu to open the "Command Prompt."
Enter "nslookup" into the "Command Prompt" window, and press "Enter". Type "set debug" and press "Enter" once more.
Enter the domain name or IP address of your choice into the "Command Prompt" window, and press "Enter." The value for the TTL statistic will be shown under "Answers." This value will be denominated in seconds (e.g., "54 secs").
Enter another domain name or IP address or type "Exit" to leave "nslookup." Type "Exit" to close the "Command Prompt."
- To translate the domain's TTL value from seconds into minutes or hours, keep in mind that there are 60 seconds in a minute. These values can be translated by multiplying the number of seconds in an hour to the number of minutes in a second. A TTL value of "3600" means that the domain is to be cached for 1 hour before the DNS server refreshes the cache. A value of "86400" can be translated into "24 hours."