Inconsistent A record lookup results for @

[Carnell Chan]

Hi there,

Recently I observed a very weird phenomenon, that some of the DNS requests for my domain will return 0.0.0.0 on the primary local DNS while resolve correctly on the secondary local DNS. This happens elsewhere too (on several public DNS), but not everywhere.

The questionable domain query is for @.cxqn.info., which I set an A record directly at ZoneEdit (no URL Forwarder etc.). Here are several query results:

• $ dig cxqn.info @ns19.zoneedit.com
  cxqn.info. 450 IN A 172.96.126.76
  
• $ dig cxqn.info @8.8.8.8 (Google Public DNS)
  cxqn.info. 449 IN A 172.96.126.76
  
• $ dig cxqn.info @208.67.222.222 (OpenDNS primary)
  cxqn.info. 23287 IN A 0.0.0.0
• $ dig cxqn.info @208.67.220.220 (OpenDNS secondary)
  cxqn.info. 450 IN A 172.96.126.76
  
• $ dig cxqn.info @dns-a.tsinghua.edu.cn (institutional DNS primary)
  cxqn.info. 18753 IN A 0.0.0.0
  
• $ dig cxqn.info @dns-b.tsinghua.edu.cn (institutional DNS secondary)
  cxqn.info. 5444 IN A 172.96.126.76
  
• $ dig cxqn.info @219.141.136.10 (ISP DNS primary, China Telecom Beijing)
  cxqn.info. 450 IN A 172.96.126.76
  
• $ dig cxqn.info @219.141.136.10 (ISP DNS secondary, China Telecom Beijing)
  cxqn.info. IN A

Since the responses from both ZoneEdit servers look very legit, I'm not sure about the cause. It might be because I added AAAA records recently...
Can anyone suggest some probable cause? Thanks in advance!

 

[El.]

Hi,

Your lookup request failures may be due to communication errors between the local or public name servers you queried, and our name servers.

Regrettably, we cannot troubleshoot why a local or public name server is not querying an authoritative name server.

When checked, I see:

dig +short cxqn.info @208.67.222.222
172.96.126.76

dig +short cxqn.info @dns-a.tsinghua.edu.cn
;; connection timed out; no servers could be reached