kh.edu.tw DNS Report

Health Score: 61%

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Checked: 2 months before

Parent

NS records at parent servers

dns2.kh.edu.tw [ 163.28.136.10 ]
dns1.kh.edu.tw [ 163.28.136.2 ]
dns.kh.edu.tw [ 163.28.136.14 ]
ns.ks.edu.tw [ 163.16.1.12 ]
dwb.ks.edu.tw [ 163.16.1.23 ]
[These were obtained from moestar.edu.tw.]

Glue at parent nameservers 7/7

SUCCESS Parent nameservers know A records for your domain, Very good !

NS

Mismatched glue 7/7

SUCCESS The DNS report did not detect any discrepancies between the glue provided by the parent servers and that provided by your authoritative DNS servers.

Nameservers A records 7/7

SUCCESS Nameservers do include corresponding A records when asked for your NS records. This ensures that your DNS servers know the A records corresponding to all your NS records.

Nameservers report identical NS records 0/7

The NS records at your nameservers are different

Nameservers respond 0/10

Some nameservers does not respond:
2001:288:8201:1::10
2001:288:8201:1::2
2001:288:8201:1::14
2001:288:8401::2
2001:288:8401::3

Nameserver name validity 7/7

SUCCESS All of the NS records that your nameservers report are valid (no IPs or partial domain names).

Number of nameservers 5/5

SUCCESS You have 5 nameservers. You must have at least 2 nameservers (RFC2182 section 5 recommends at least 3 nameservers), and preferably no more than 7.

Lame nameservers 7/7

SUCCESS All the nameservers listed at the parent servers answer authoritatively for your domain.

Missing (stealth) nameservers 7/7

SUCCESS All your nameservers are also listed at the parent servers.

Root missing nameservers 0/7

DANGER There are nameservers not listed at your nameservers:
dns2.kh.edu.tw.
dns1.kh.edu.tw.
dns.kh.edu.tw.
ns.ks.edu.tw.
dwb.ks.edu.tw.

Nameservers on separate class C's 7/7

SUCCESS Nameservers are in a different networks.

public IPs 7/7

SUCCESS All of your NS records appear to use public IPs.

SOA

SOA record

SOA record is:
Hostmaster email
Serial
Refresh
Retry
Expire
TTL

Serial agreement 0/7

DANGER Some nameservers have a different soa serial number That can occur because of recent master update (slave have not loaded master zone yet) or the is a problem in DNS.

SOA MNAME 0/3

DANGER SOA (Start of Authority) record states that your master (primary) name server is: , but that server is not listed at the parent servers.

Serial value 0/1

WARNING SOA serial number is: This not appears to be in the recommended format of YYYYMMDDnn, where 'nn' is the revision. This number must be incremented every time you make a DNS change.

Refresh value 0/1

WARNING SOA Retry interval is : seconds. This seems too small. (Values about 3600-7200 seconds is good if not using DNS NOTIFY; RFC1912 2.2 recommends a value between 1200 to 43200 seconds (20 minutes to 12 hours)). This value determines how often secondary/slave nameservers check with the master for updates.

Retry value 0/1

WARNING SOA Retry interval is : seconds. This seems too small. (Values about 120-7200 seconds is good). The retry value is the amount of time your secondary/slave nameservers will wait to contact the master nameserver again if the last attempt failed.

Expire value 0/1

WARNING SOA Expire time is : seconds. This seems too small. (Values 604800 to 2419200 seconds (1-4 weeks) is good). RFC1912 suggests 2-4 weeks. This is how long a secondary/slave nameserver will wait before considering its DNS data stale if it can't reach the primary nameserver.

TTL value 0/1

WARNING SOA Expire time is : seconds. This seems too small. (about 300 to 86400 seconds or 5 min - 24 hours is good). RFC2308 suggests a value of 1-3 hours. This value used to determine the default (technically, minimum) TTL (time-to-live) for DNS entries, but now is used for negative caching.

Info

DNS trace

Trace to kh.edu.tw
lookup kh.edu.tw at A.ROOT-SERVERS.NET(198.41.0.4) 13 ms
A.ROOT-SERVERS.NET(198.41.0.4) refer to g.dns.tw(220.229.225.195)
lookup kh.edu.tw at g.dns.tw(220.229.225.195) 201 ms
g.dns.tw(220.229.225.195) refer to c.twnic.net.tw(168.95.192.10)
lookup kh.edu.tw at c.twnic.net.tw(168.95.192.10) 199 ms
c.twnic.net.tw(168.95.192.10) refer to dwb.ks.edu.tw(163.16.1.23)
lookup kh.edu.tw at dwb.ks.edu.tw(163.16.1.23) 218 ms
RECORD does not exist
Total time: 631 ms