DNS Messages and Records
Ron Aitchison · Apress eBooks · 2011
This chapter describes the binary messages and resource record (RR) formats that pass between DNS servers. These messages comprise what is sometimes called the wire format because it is the format sent across the network, or wire , in the understated slang of the network professional. While it’s primarily a reference section with copious descriptions of bits and bytes, this chapter is also answers the following questions and more for the naturally curious reader: What is a referral? When a dig command is issued, just what are the ANSWER SECTIONs and AUTHORITY SECTIONs that are returned? Why are there only 13 root-servers (because of packet size considerations)? These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.