DNS (Domain Name System) domain name system, the Internet is a service. It acts as a distributed database of domain names and IP addresses will be mapped each other, it can make it easier to access the Internet. DNS uses TCP and UDP port 53. Currently, for every level domain name length limit is 63 characters, the total length of the domain name can not be more than 253 characters.
DNS system, common resource record types are:
- Host record (A record): RFC 1035 defined, A is an important recording record name resolution, it is mapped to the specific host name corresponding to the IP address of the host;
- Alias record (CNAME record): RFC 1035 definitions, CNAME record for an alias pointing to an A record, so you do not need to create a new additional A record for a new name;
- IPv6 host record (AAAA record): RFC 3596 is defined, the A record corresponding to, for mapping the specific host name to an address of the IPv6 host;
- Service location record (SRV record): RFC 2782 defines, for defining the location server providing a particular service, such as a host, port, and the like;
- NAPTR record: RFC 3403 definition, which provides regular expression way to map a domain name. NAPTR record a very well-known application for ENUM query;
This guy is lazy, directly from the Baidu's.
〗 〖Adhere to a Xiu
Reproduced in: https: //www.jianshu.com/p/6f4aea1fcd66