In the Domain Name System (DNS), the TTL (Time To Live) indicates how long a DNS setting is valid until it is updated by the overlying nameserver.
ISPs use caches for DNS records (store the record locally rather than retrieving fresh data from nameservers) to speed up web browsing and reduce traffic, which delay the time until changes are visible to your visitors. Some ISPs ignore TTL settings and only update their cached records every two to three days. Although we ensure 1 hour for A/AAAA/MX/TXT/CNAME-records and 48 hours for NS-records, it might take up to 72 hours until the settings are visible.
If you change your domain name's nameservers, we submit your change request to the registry within minutes, and they publish your primary NS (nameserver) records within their root zone. Most registries update their zones continously.
For example, VeriSign refreshes zones for .com domain names every three minutes. However, not all registries make updates that often. Registries may protect their root nameservers from overuse by setting a high TTL of up to 48 hours or more for those NS records.
|Updated Record||TTL on 1&1 Nameservers||Maximum propagation time|
|A/AAA/MX/TXTCNAME||up to 1 hour||up to 72 hours|
|NS||up to 48 hours||up to 72 hours|