Details
DNS CNAME records are specified in RFC 1034 and clarified in Section 10 of RFC 2181.
CNAME records are handled specially in the domain name system, and have several restrictions on their use. When a DNS resolver encounters a CNAME record while looking for a regular resource record, it will restart the query using the canonical name instead of the original name. (If the resolver is specifically told to look for CNAME records, the canonical name (right-hand side) is returned, rather than restarting the query.) The canonical name that a CNAME record points to can be anywhere in the DNS, whether local or on a remote server in a different DNS zone.
For example, if there is a DNS zone as follows:
NAME TYPE VALUE -------------------------------------------------- foo.example.com. CNAME bar.example.com. bar.example.com. A 192.0.2.23When an A record lookup for foo.example.com is done, the resolver will see a CNAME record and restart the checking at bar.example.com and will then return 192.0.2.23.
Read more about this topic: CNAME Record
Famous quotes containing the word details:
“Anyone can see that to write Uncle Tom’s Cabin on the knee in the kitchen, with constant calls to cooking and other details of housework to punctuate the paragraphs, was a more difficult achievement than to write it at leisure in a quiet room.”
—Anna Garlin Spencer (1851–1931)
“If my sons are to become the kind of men our daughters would be pleased to live among, attention to domestic details is critical. The hostilities that arise over housework...are crushing the daughters of my generation....Change takes time, but men’s continued obliviousness to home responsibilities is causing women everywhere to expire of trivialities.”
—Mary Kay Blakely (20th century)
“Patience is a most necessary qualification for business; many a man would rather you heard his story than granted his request. One must seem to hear the unreasonable demands of the petulant, unmoved, and the tedious details of the dull, untired. That is the least price that a man must pay for a high station.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)