我测试了一下，我也 ping 不通那个 ip 。
C:\Users\dream>ping rdp.mknetwork.net

Pinging chn-cu1.mknetwork.net [157.0.163.52] with 32 bytes of data:
Reply from 157.0.163.52: bytes=32 time=237ms TTL=39
Reply from 157.0.163.52: bytes=32 time=226ms TTL=39
Reply from 157.0.163.52: bytes=32 time=238ms TTL=39

Ping statistics for 157.0.163.52:
Packets: Sent = 3, Received = 3, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 226ms, Maximum = 238ms, Average = 233ms
Control-C
^C
C:\Users\dream>ping 221.6.4.66

Pinging 221.6.4.66 with 32 bytes of data:
Request timed out.
Request timed out.

Ping statistics for 221.6.4.66:
Packets: Sent = 2, Received = 0, Lost = 2 (100% loss),
Control-C