[bizarre domain name cannot be resolved] windows server appears locally

When the system runs business for a period of time, it always finds that the local domain name of the system is inexplicably unable to resolve the domain name. Domain names such as ping www.baidu.com always prompt ping request could not find host

Manually modify the DNS address to overseas 8.8.8.8, domestic 114.114.114.114 and other dns IP are not solved. Restart the system and work normally.

For the first time, I thought there was something wrong with the cloud server system. An almighty restart. And then he showed up. There are no practical errors in checking the system log.

This time, decided to solve it once and for all. Start with the original dns protocol.

Solution:

One: the parsing of some columns of DNS follows the UDP protocol and accesses port 53 of the DNS server.

Netstat-an | findstr 53

Couldn't find it.

Two: find an agreement

Netstat-ano | findstr UDP

It is found that the udp port is listening on more than 10000 ports, and they are all id 3832 of the same process.

Found the problem. This process takes up all the random ports of UDP. DNS client cannot generate a UDP random port to access external DNS server port 53 and cannot accept data. Therefore, no matter restart the dns client service or change the dns IP locally, it cannot be solved.

Solve the process id 3832 program, release the startup UDP random port, the problem is solved.

I hope it will be a good help for all of you to encounter this kind of problem.