| Parent | pass | NS records at parent servers | Your NS records at the parent servers are: ns1.rbsov.bbc.co.uk. ns1.tcams.bbc.co.uk. ns1.thdow.bbc.co.uk. [These were obtained from e.gtld-servers.net.] |
| warn | Glue at parent nameservers | WARNING. The parent servers (I checked withe.gtld-servers.net.) are not providing glue for all your nameservers. This means that they are supplying the NS records (host.example.com), but not supplying the A records That may cause some extra miliseconds in DNS. This will usually occur if your DNS servers are not in the same TLD as your domain | |
| NS | info | NS records at your nameservers | Your NS records at your nameservers are: ns1.thdow.bbc.co.uk. [212.58.240.163 ] ns1.rbsov.bbc.co.uk. [212.58.241.67 ] ns1.tcams.bbc.co.uk. [212.72.49.3 ] |
| skip | Mismatched glue | Skip comparing the glue provided by the parent servers and that provided by your authoritative DNS servers, as root servers do not provide glue | |
| pass | No NS A records at nameservers | OK. Your 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. | |
| pass | All nameservers report identical NS records | OK. The NS records at all your nameservers are identical. | |
| pass | All nameservers respond | OK. All of your nameservers listed at the parent nameservers responded. | |
| pass | Nameserver name validity | OK. All of the NS records that your nameservers report seem valid (no IPs or partial domain names). | |
| pass | Number of nameservers | OK. You have 3 nameservers. You must have at least 2 nameservers (RFC2182 section 5 recommends at least 3 nameservers), and preferably no more than 7. | |
| pass | Lame nameservers | OK. All the nameservers listed at the parent servers answer authoritatively for your domain. | |
| pass | Missing (stealth) nameservers | OK. All 2 of your nameservers (as reported by your nameservers) are also listed at the parent servers. | |
| pass | Missing nameservers 2 | OK. All of the nameservers listed at the parent nameservers are also listed as NS records at your nameservers. | |
| pass | Nameservers on separate class C's | Your nameservers seems to be in different networks. | |
| pass | All NS IPs public | OK. All of your NS records appear to use public IPs. If there were any private IPs, they would not be reachable, causing DNS delays. | |
| SOA | info | SOA record | Your SOA record is: Primary nameserver: ns.bbc.co.uk. Hostmaster E-mail address: hostmaster.bbc.co.uk. Serial #: 2013060500 Refresh: 1800 Retry: 600 Expire: 864000 Default TTL:86400 |
| pass | NS agreement on SOA Serial # | OK. All your nameservers agree that your SOA serial number is 2013060500. That means that all your nameservers are using the same data. | |
| fail | SOA MNAME Check | ERROR: Your SOA (Start of Authority) record states that your master (primary) name server is: ns.bbc.co.uk. That server is not listed at the parent servers, which is not correct. | |
| pass | SOA Serial Number | OK. Your SOA serial number is: 2013060500. 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. | |
| pass | SOA REFRESH value | Your SOA REFRESH interval is : 1800 seconds. This seems normal (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. | |
| pass | SOA RETRY value | Your SOA RETRY interval is : 600 seconds. This seems normal (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. | |
| pass | SOA EXPIRE value | Your SOA EXPIRE time is : 864000 seconds. This seems normal (about 1209600 to 2419200 seconds (2-4 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. | |
| pass | SOA MINIMUM TTL value | Your SOA MINIMUM TTL is : 86400 seconds. This seems normal (about 3,600 to 86400 seconds or 1-24 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. | |