DNS: Records and Messages
Explore the structure and function of DNS resource records including A, CNAME, and MX types. Understand how DNS queries and replies form messages, their format, and the role of zone files and transfers. This lesson helps grasp how DNS operates as a distributed database supporting domain name resolution.
We'll cover the following...
We'll cover the following...
Resource Records
The DNS distributed database consists of entities called RRs, or Resource Records.
Format
RRs contain some or all of the following values:
- Name of the domain.
- Resource data (RDATA) provides information appropriate for the type of resource record.
- Type of the resource record. We will discuss these shortly.
- Time-to-live (TTL) is how long the record should be cached by the client in seconds.
- DNS Class. There a many types of classes but we’re mainly concerned with
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