How does centos7 locate and solve the problem of slow DNS resolution when accessing the public network?

the server is located in Guangdong. The following three groups of dns have been used, and the dns parsing time is more than 5 seconds

. < table > < thead > < tr > < th align= "center" > serial number < / th > < th align= "center" > dns1 < / th > < th align= "center" > dns2 < / th > < / tr > < / thead > < tbody > < tr > < td align= "center" > 1 < / td > < td align= "center" > 119.29.29.29 < / td > < td align= "center" > 182.254.116.116 < / td > < / tr > < tr > < td align= "center" > 2 < / td > < td align= "center" > 114.114.114.114 < / td > < td align= "center" > 114.114.114.115 < / td > < / tr > < tr > < td align= "center" > 3 < / td > < td align= "center" > 202.96.128.68 < / td > < td align= "center" > 202.96.128.86 < / td > < / tr > < / tbody > < / table >

Network Test 1 (curl)
the following is a test in which the server uses curl to access the sf home page, omitting the sf home page code (it can be accessed successfully, in which the contents of the curl_setting file refer to https://www.cnblogs.com/hwy89.)

-sharp curl -w "@curl_setting" https://segmentfault.com/

        time_namelookup:  5.515
           time_connect:  5.554
        time_appconnect:  5.805
       time_pretransfer:  5.805
          time_redirect:  0.000
     time_starttransfer:  6.022
                        ----------
             time_total:  6.355

Network Test 2 (mtr mode)

-sharp mtr -rw https://segmentfault.com/
Failed to resolve host: Temporary failure in name resolution

< hr >

it"s strange that dns parsing can be successful in curl mode, but not in mtr mode! Excuse me, what"s going on?