The DNS convention utilizes two kinds of DNS messages, questions and answers, and they both have a similar configuration. Each message comprises of a header and four areas: question, answer, expert, and an extra space. A header field (banners) controls the substance of these four segments.
The header area contains the accompanying fields router ip address routeripaddress.info
: Identification, Flags, Number of inquiries, Number of answers, Number of power asset records (RRs), and Number of extra RRs. The recognizable proof field can be utilized to coordinate reactions with questions. The banner field comprises of a few sub-fields. The first is a solitary piece which shows if the message is an inquiry (0) or an answer (1). The second sub-field comprises of four bits showing the sort of inquiry, or the kind of question this message is a reaction to. 0 is a standard inquiry, 1 a reverse question, 2 is a server status ask. A solitary piece sub-field shows if the DNS server is legitimate for the questioned hostname. Another single-piece sub-field demonstrates if the customer needs to send a recursive question ("RD"). The following single-piece sub-field shows if the answering DNS server bolsters recursion ("RA"), as not all DNS servers are designed to do this assignment. Another sub-field demonstrates if the message was truncated for reasons unknown ("TC"), and a four-piece sub-field is utilized for mistake codes. The inquiry segment contains the space name and kind of record (An, AAAA, MX, TXT, and so forth.) being settled. The area name is broken into discrete names which are connected; each mark is prefixed by the length of that name. The appropriate response segment has the asset records of the questioned name. An area name may happen in numerous records on the off chance that it has various IP addresses related.