yytc.com.tw DNS Report

Health Score: 94%

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Checked: 5 months before

Parent

NS records at parent servers

dns.yytc.com.tw [ 203.66.72.202 ]
[These were obtained from c.twnic.net.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 7/7

SUCCESS The NS records at all your nameservers are identical.

Nameservers respond 10/10

SUCCESS All of your nameservers listed at the parent nameservers responded.

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 0/5

DANGER You have less then 2 nameservers, that may cause downtime

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 7/7

SUCCESS All of the nameservers listed at the parent nameservers are also listed as NS records at your nameservers.

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
henry.yytc.com.tw
Serial
2019051505
Refresh
3600
Retry
600
Expire
86400
TTL
3600

Serial agreement 7/7

SUCCESS All your nameservers agree that your SOA serial number is 2019051505 That means that all your nameservers are using the same data.

SOA MNAME 3/3

SUCCESS SOA (Start of Authority) record states that your master (primary) name server is: dns.yytc.com.tw That server is listed at the parent servers, which is correct.

Serial value 1/1

SUCCESS SOA serial number is: 2019051505 This 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 1/1

SUCCESS SOA Retry interval is : 3600 seconds. This seems OK. (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 1/1

SUCCESS SOA Retry interval is : 600 seconds. This seems OK. (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 : 86400 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 1/1

SUCCESS SOA Expire time is : 3600 seconds. This seems OK. (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 yytc.com.tw
lookup yytc.com.tw at A.ROOT-SERVERS.NET(198.41.0.4) 41 ms
A.ROOT-SERVERS.NET(198.41.0.4) refer to g.dns.tw(220.229.225.195)
lookup yytc.com.tw at g.dns.tw(220.229.225.195) 216 ms
g.dns.tw(220.229.225.195) refer to a.twnic.net.tw(211.73.64.22)
lookup yytc.com.tw at a.twnic.net.tw(211.73.64.22) 209 ms
a.twnic.net.tw(211.73.64.22) refer to dns.yytc.com.tw(203.66.72.202)
lookup yytc.com.tw at dns.yytc.com.tw(203.66.72.202) 208 ms
got A record 'yytc.com.tw IN A 203.66.72.202' from yytc.com.tw(203.66.72.202)
Total time: 674 ms