Computers are useless unless they perform some service.
Red Hat Linux machines come ready to perform many services, making them powerful choices for Internet application servers.
IP addresses and ports form the foundation for these Internet services. To help users, the Domain Name System assigns names to IP address,
and Linux itself assigns names to ports.
Finally, servers may operate as either standalone or transient; deciding which method a particular server should use is a frequent administrator concern.
Having completed this module, you should now be able to:
Identify the properties of Internet Protocol
Describe an IP address
Relate TCP and UDP protocols to IP
Define port numbers
Explain the relationship between port names and numbers
Configure port names
Describe the function of the Domain Name System
State the differences between a standalone and a transient network server
List the advantages and disadvantages of standalone and transient network servers
The following terms were introduced in this module:
Checksum: A value computed from a quantity of data and transmitted alongside the data.
The receiver can verify the data's integrity by computing the checksum again and comparing the newly computed value to the transmitted one.
- Domain Name System (DNS): The Internet system for translating IP addresses into names and vice-versa.
- Fully-Qualified Domain Names (FQDN): A domain name that has all required DNS information: the host, network, and top-level domain.
- Internet Assigned Numbers Authority (IANA): The IANA is responsible for assigned standard port numbers to well-known Internet services, such as HTTP, FTP, and DNS.
- Internet Protocol (IP): The fundamental unit for sending data across the Internet.
- Protocol: A grammar for communicating an idea between two end points.
- Standalone server: A server that opens, maintains, and closes its own network connections.
- Superserver: A server process responsible for listening on a group of ports and spawning other servers when connections arrive for them.
- Transient servers: A server that performs its service for a single client, starting fresh every time a client request arrives. Transient servers do not listen for client requests, but rather are spawned by another program.
- Transmission Control Protocol (TCP: A connected, reliable method for sending data across a network.
- User Datagram Protocol (UDP: A connectionless, unreliable method for delivering packets across the Internet.
- Well-known services (WKS): WKSs are services that are prevalent across the Internet. Examples include HTTP for World Wide Web traffic, FTP for File Transfer Protocol, and DNS for the Domain Name System.
The next module describes how Linux provides network services.
Before moving to the next module, click the Quiz link below to check your understanding of the concepts presented in this module.
Domain Name System - Quiz