Long DNS Time
Problem description
online tasks
Troubleshooting ideas
1.
Recurrence, specify 202.138.120.86 and find that DNS Time is still very long.
2. View the task data of DNS in the region by capturing packets
From the analysis of the packet capture of www.google.com and www.facebook.com, it can be seen that the DNS server "103.253.154.74" is completely unavailable and has not responded to any A record analysis of Request.
Through the above data, DNS Time is still very slow, indicating that the DNS resolution in this area is indeed very slow, and it is not the customer's problem. Even if other DNS in the area are replaced, the same problem will occur.
Problem summary
1.
If there is a problem, you can report Probe Group to replace the DNS of Probe, but you cannot specify it. You can only Probe Group evaluate the DNS with higher Availability in the area, because the Probe does not only serve one task.
When communicating this issue with the customer, the customer hopes to specify 8.8.8.8 or 8.8.4.4. This is not possible and cannot be used.
2.
This is a demand issue and has been scheduled for processing.