Expediting Propagation Time
This article covers the subject of expediting propagation time.
Updating DNS nameserver records can result in downtime or intermittent resolution of your domain for up to 48 hours while the updates propagate across all the DNS servers around the world. At HostDime, we configure our authoritative servers to update as quickly as possible. However, propagation time also depends on some factors out of our control.
Your Domain Registrar
If you update your DNS nameservers in your CORE Client Area, we push those record changes to the master registrar within a few minutes or less so that they can update their root zone file. Most master registries update their zones quickly while others set their TTLs (see below) to longer wait times which results in a longer propagation time.
Your ISP
Once your domain name registrar updates their root zone file, those changes then have to get pushed out to each ISP around the world. Just as different registrars have different TTLs (see below), ISPs do as well and your records will get updated as your ISP "accepts" that change. As such, your domain may not resolve for you but will resolve for some of your clients/colleagues depending on your ISP and vice versa.
TTL (Time to Live) Settings
Each DNS server can specify a TTL (Time to Live) setting in their DNS zone. If you have cPanel/WHM this can be modified in the DNS Zone File for each individual domain. TTL is the time period for which servers cache your DNS information. If you set your TTL for domain.com to 6 hours, your server will store that record's information locally for 6 hours before trying to retrieve updated information from your authoritative nameservers. The shorter your TTL settings are, the quicker your propagation speed will be at the server level, though you will still need to wait on your ISP as well as your domain registrar. However, shortening your TTL settings will create more queries to your authoritative nameservers, and that increased load could slow your server's processing time. It is possible to shorten the TTL setting, wait for full propagation, and then extend it again so as not to create too many queries and cause any adverse issues. Keep in mind that if you do not have access to DNS Zone management within WHM you'll need to contact our support department to assist you with shortening your TTL settings.