. to cn: Authoritative AAAA records exist for ns.cernet.net, but there are no corresponding AAAA glue records.
. to cn: The glue address(es) for ns.cernet.net (202.112.0.44) differed from its authoritative address(es) (103.137.60.44, 202.112.0.44).
com.cn/SOA: No response was received until the UDP payload size was decreased, indicating that the server might be attempting to send a payload that exceeds the path maximum transmission unit (PMTU) size. (203.119.25.1, UDP_-_EDNS0_4096_D_KN_0x20)