ru zone: The server(s) were not responsive to queries over UDP. See RFC 1035, Sec. 4.2. (2001:678:14:0:193:232:156:17)
Warnings (3)
yandex.ru/AAAA: 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. See RFC 6891, Sec. 6.2.6. (2a02:6b8:0:1::1, UDP_-_EDNS0_4096_D_KN)
yandex.ru/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. See RFC 6891, Sec. 6.2.6. (2a02:6b8::1, 2a02:6b8:0:1::1, UDP_-_EDNS0_4096_D_KN, UDP_-_EDNS0_4096_D_KN_0x20)
yandex.ru/DNSKEY has warnings; select the "Denial of existence" DNSSEC option to see them.