Generally, we determine that the DNS resolution is not effective based on two points: inability to ping the domain to get an IP and inability to open the page.

1. Unable to ping the domain

Possible reasons for this situation are as follows:

(1) The record has not been correctly added

Remember, if the line type is not set to default, some users will not be able to access it.

(2) The domain’s DNS modification has not yet taken effect

DNS modifications take some time to fully take effect. Just a few hours is not enough for complete effectiveness. If the local ISP’s DNS server has not fully refreshed your domain’s records, you will not be able to ping the IP. The solution is to wait; the waiting time will not exceed 48 hours.

(3) The domain’s DNS records are cached

Caching can occur on Windows (all Windows systems cache), the router (if accessing the internet via a router), and the local ISP’s DNS server (DNS servers use recursion).

Solutions:

(1) If connecting directly to the internet via Windows, go to Start - Run - ipconfig /flushdns. Then wait half a minute before pinging again, which usually resolves the issue.

(2) If accessing the internet via a router, clear the router’s DNS cache. This can be done by restarting the router. If you cannot restart the router, change the DNS server address on Windows to another address. Note: After clearing the router’s cache using this method, you also need to run the ipconfig /flushdns command.

(3) If the above methods do not work, the local ISP’s DNS server must have cached the data. In this case, change the DNS server address on Windows to another address, or wait for the local ISP’s DNS server to clear its cache (usually within an hour).

Note: Linux and Unix systems do not cache DNS records. Mac OS X systems can clear the DNS cache by using the killall lookupd command.

2. Unable to open the page

As long as the page returns an error code, the DNS resolution has already taken effect. You need to check the server configuration.

Below are common error code pages:

(list of common error codes here)

Any of the above pages indicate issues unrelated to DNS resolution. Please check the server configuration.