Question 1

What is a lame delegation?

Accepted Answer

A lame delegation occurs when a domain's parent zone lists a nameserver as authoritative, but that nameserver either doesn't respond or doesn't have authoritative data for the zone. This causes random DNS resolution failures. It commonly happens when a DNS provider is changed without updating all NS records.

Question 2

What are glue records?

Accepted Answer

Glue records are A/AAAA records for nameservers that are within the zone they serve. For example, if ns1.yourdomain.com is your nameserver, the registry needs to know ns1's IP address before it can resolve yourdomain.com. This IP is the 'glue' record, stored in the parent zone.

Question 3

What is a SOA record and what does the serial number mean?

Accepted Answer

The SOA (Start of Authority) record marks the beginning of a DNS zone and contains the primary nameserver, responsible party email, and zone parameters including the serial number. The serial number is incremented each time the zone is updated. If SOA serials differ across nameservers, the zone hasn't fully replicated.