域名更改DNS后，检测dns不同地区刷新情况
也是很好的学习网络网站：
https://dnschecker.org
https://dnsmap.io/
也可以命令行检测：
(base) [~] dig @1.1.1.1 +short NS xxxx.com
原文地址 vercel.com
If you have recently changed DNS records, you're not able to see your website and the Vercel Dashboard shows that the domain is configured correctly then it's likely that you have a cached DNS record on your local device or network.
You can test this by using a different device on a different internet connection (a smartphone using mobile data usually works best).
This cache is cleared automatically after a certain period of time (usually anywhere from 1-24 hours), however it can be manually cleared by restarting your local computer or your local firewall/router. You can also clear this via your operating system's commands, however this varies for each device/operating system and would recommend researching how to do this for your specific device.
Nameserver Changes
If you have changed the nameservers with your current domain registrar then it usually takes up to 48 hours for these to be reflected globally. This is not something that Vercel has any control over and for certain registrars, this can be slower.
Once nameservers have been changed, you may wish to check the progress of the propagation. There are many third-party tools that do this, such as DNS Checker and DNS Map - these show the state of your DNS records in different regions of the world.
You can also use the terminal to check the nameservers for your domain using specific DNS providers, some examples are found below:
dig @8.8.8.8 +short NS vercel.com
Querying Google DNS for the vercel.com nameservers.
dig @1.1.1.1 +short NS vercel.com
Querying Cloudflare DNS for the vercel.com nameservers.
dig @ns1.vercel-dns.com +short NS vercel.com
Querying Vercel DNS for the vercel.com nameservers.
CNAME Record Changes
Unlike nameserver changes, propagation of CNAME records are usually very quick to propagate.
You can check the propagation progress of CNAME records for your domain with third-party tools like DNS Checker and DNS Map in the same way you can for nameservers.
You can also use the terminal to check the CNAME record for your domain using specific DNS providers, some examples are found below:
dig @8.8.8.8 +short CNAME www.vercel.com
Querying Google DNS for the www.vercel.com CNAME record value.
dig @1.1.1.1 +short CNAME www.vercel.com
Querying Cloudflare DNS for the www.vercel.com CNAME record value.
dig @ns1.vercel-dns.com +short CNAME www.vercel.com
Querying Vercel DNS for the www.vercel.com CNAME record value.
A Record Changes
In the same way as CNAME records, A records usually propagate very quickly.
You can check the propagation progress of A records for your domain with third-party tools like DNS Checker and DNS Map in the same way you can for CNAME.
You can also use the terminal to check the A record for your domain using specific DNS providers, some examples are found below:
dig @8.8.8.8 +short A vercel.com
Querying Google DNS for the vercel.com A record value.
dig @1.1.1.1 +short A vercel.com
Querying Cloudflare DNS for the vercel.com A record value.
dig @ns1.vercel-dns.com +short A vercel.com