Chapter 13. Cloud DNS
An overview and history of the Domain Name System (DNS)
How the Cloud DNS API works
How Cloud DNS pricing is calculated
An example of assigning DNS names to VMs at startup
Broken down
Addressed
Transmitted
Routed
Received
Defines how applications create communication channels
Manages how a message is broken down to be transmitted
IP - Defines how to address and route packets for delivery
Application layer - HTTP, FTP, SMTP, SMNP
Transport layer
Network layer
Physical layer
Non proprietary and easily modified
Compatible with all operating systems, hardware, and networks
Highly scalable
TCP/IP is a set of network protocols that enable communication between computers.
Network protocols are rules or standards that govern network communications.
It was developed in the 1970s and adopted as the protocol standard for ARPANET (the predecessor to the Internet) in 1983.
TCP/IP specifies how data is exchanged over the internet by providing end-to-end communications that identify how it should be
broken into packets, addressed, transmitted, routed and received at the
destination.
Each gateway computer on the network checks this IP address to determine where to forward the message.
DNS is a hierarchical distributed storage system that tracks the mapping
of internet names (like www.google.com) to numerical addresses.
DNS is the internet’s phone book.
The system stores a set of “resource records,” which are the mappings
from names to numbers, and splits these records across a hierarchy
of “zones.”
Delegate responsibility for owning and updating subsets of records.
Pointing to specific numeric addresses (such as A or AAAA records).
Address Mapping record (A Record)—also known as a DNS host record, stores a hostname and its corresponding IPv4 address.
Storing arbitrary data (such as TXT records).
A TXT record (short for text record) is a type of resource record in the Domain name system (DNS) used to
provide the ability to associate arbitrary text with a host or other name,
such as human readable information about a server, network, data center,
or other accounting information.
13.1. What is Cloud DNS?
Google Cloud DNS is a managed service that acts as a DNS server and
can answer DNS queries like other servers, such as BIND.
Expose an API that makes it possible to manage DNS entries automatically.
An API for managing DNS entries, you can configure virtual machines to
automatically register a new DNS entry at boot time giving you friendly
names such as server1.mydomain.com.
13.1.1. Example DNS entries
A name server (NS) record, which is responsible for delegating ownership to other servers;
Logical” (A or AAAA) records, which point to IP addresses of a server;
Canonical name” (CNAME) record, which acts as an alias of sorts for the domain entry.
Manage these as “zone files,” which are text files stating in a special format the exact DNS records.
Cloud DNS does exactly this: exposing zones and record sets as resources that you can create and manage.
Summary
DNS is a hierarchical storage system for tracking pointers
of human-readable names to computer-understandable addresses.
Cloud DNS is a hosted, highly available set of DNS servers with
an API against which we can program.
Cloud DNS charges prices based on the number of zones
(domain names) and the number of DNS lookup requests.
No comments:
Post a Comment