ycwb.com

vip3.alidns.com, vip4.alidns.com

Found

Parent zone

com

Delegation from

a.gtld-servers.net (192.5.6.30)

NS at the parent

vip3.alidns.com, vip4.alidns.com

NS in the zone

vip3.alidns.com, vip4.alidns.com

Checks

• i

  2 nameservers

  Two nameservers meet the minimum; RFC 2182 recommends three or more for important zones: vip3.alidns.com, vip4.alidns.com.

  #6
• ✓ Parent and zone agree #7

  The parent delegation and the zone's NS records list the same nameservers.
• !

  Glue differs from the zone

  The addresses at the parent (glue) differ from the addresses in the zone: vip3.alidns.com (glue 121.40.6.163, 140.205.1.5, 170.33.32.210, 170.33.73.26, 170.33.80.10, 2408:4009:500::3, 39.103.26.212, 47.108.36.163, 47.116.84.178, 8.129.152.245, 8.212.93.3, zone 170.33.32.210, 8.212.93.3, 170.33.80.10, 140.205.1.5, 170.33.73.26, 2408:4009:500::3); vip4.alidns.com (glue 121.40.6.164, 140.205.1.6, 170.33.32.211, 170.33.73.27, 170.33.80.11, 2408:4009:500::4, 39.103.26.213, 47.108.36.164, 47.116.84.179, 8.129.152.246, 8.212.93.4, zone 170.33.73.27, 140.205.1.6, 8.212.93.4, 170.33.32.211, 170.33.80.11, 2408:4009:500::4). Update the glue at your registrar.

  #8
• ✓ All names resolve #9

  Every nameserver name has an address and is not an alias.
• i

  One address family in one network

  all IPv6 addresses are in 2408:4009:500::/48, while the other address family is spread over several networks.

  #10
• ✓ 2 autonomous systems #11

  The nameservers are spread over: AS134963 (ASEPL-AS-AP - Alibaba Cloud (Singapore) Private Limited, SG): 1 address; AS45102 (ALIBABA-CN-NET - Alibaba (US) Technology Co., Ltd., CN): 11 addresses.
• i

  All nameserver names under .com

  All nameserver names are under one TLD, so a problem with that TLD also makes the nameservers unreachable. Some operators use names under two TLDs for extra resilience.

  #12
• ✓ All reachable over IPv6 #13

  Every nameserver has an IPv6 address.

serial 2026081712 · primary vip3.alidns.com

Found

Primary (MNAME)

vip3.alidns.com

Contact (RNAME)

hostmaster.hichina.com

Serial

2026081712

Refresh / retry

3600 s / 1200 s

Expire

86400 s

Negative TTL

600 s

Serial per nameserver

Checks

• !

  Serials differ

  The nameservers serve different versions of the zone: 2013052800 on vip3.alidns.com (170.33.80.10), vip3.alidns.com (2408:4009:500::3), vip4.alidns.com (170.33.73.27), vip4.alidns.com (140.205.1.6), vip4.alidns.com (2408:4009:500::4); 2026081712 on vip3.alidns.com (170.33.32.210); 2026081810 on vip3.alidns.com (8.212.93.3), vip3.alidns.com (140.205.1.5), vip3.alidns.com (170.33.73.26), vip4.alidns.com (8.212.93.4), vip4.alidns.com (170.33.80.11); 2026082516 on vip4.alidns.com (170.33.32.211). This is normal for a few minutes after a change; if it lasts, zone transfers to the secondaries are failing.

  #22
• !

  Unusual SOA timers

  expire 1d is shorter than 7d; secondaries stop answering too soon when the primary is down. Current values: refresh 1h, retry 20m, expire 1d, negative TTL 10m.

  #23
• ✓ Primary is a public nameserver #24

  The primary nameserver vip3.alidns.com is one of the listed nameservers.
• ✓ Contact hostmaster@hichina.com #25

  The SOA RNAME hostmaster.hichina.com means hostmaster@hichina.com.
• ✓ Date-based serial #26

  The serial 2026081712 follows the YYYYMMDDnn convention (2026-08-17).

Not signed

Found

Validated by resolver

no

Checks

• !

  Not signed

  The zone is not signed with DNSSEC, so answers can be spoofed. Enable DNSSEC at your DNS provider and publish the DS record at your registrar.

  #27