Skip to main content
Engineering LibreTexts

10-B.2-3: Server Roles in Linux (continued)

  • Page ID
    40569
  • Name Server/DNS Services

    The Domain Name System (DNS) provides the database to be used in the translation from human-readable hostnames, such as www.opensource.com, to IP addresses, like 54.204.39.132, so that your internet-connected computers and other devices can access them. The primary function of the BIND (Berkeley Internet Name Domain) software is that of a domain name resolver that uses that database. There is other name resolver software, but BIND is currently the most widely used DNS software on the internet. The terms name server, DNS, and resolver will be used pretty much interchangeably throughout this article.

    Without these name resolver services, surfing the web as freely and easily as we do would be nearly impossible. As humans, we tend to do better with names like Opensource.com, while computers do much better with numbers like 54.204.39.132. Therefore, we need a translation service to convert the names that are easy for us to the numbers that are easy for our computers.

    NTP Services

    The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks. In operation since before 1985, NTP is one of the oldest Internet protocols in current use. NTP was designed by David L. Mills of the University of Delaware.

    NTP servers connectioning to multiple other servers to maintain a proper time based on distance and network lag.
    Figure \(\PageIndex{1}\): NTP In Action. (""Network_Time_Protocol_servers_and_clients.svg" by Benjamin D. EshamWikiemedia Commons is in the Public Domain, CC0)

    NTP is intended to synchronize all participating computers to within a few milliseconds of Coordinated Universal Time (UTC). NTP can usually maintain time to within tens of milliseconds over the public Internet, and can achieve better than one millisecond accuracy in local area networks under ideal conditions. Asymmetric routes and network congestion can cause errors of 100 ms or more.

    Networked devices are connected to another device to obtain NTP services. This continues until at some point in the network a device is connected to an actual atomic clock or other device that keeps the time.

    Proxy Services

    A proxy server is a server that behaves as an intermediary between a desktop computer and the internet. The proxy server allows a client machine to make an indirect connection to network servers and services. There are many reasons why you might want to include a proxy server on your network:

    • Share internet connection on a network
    • Speed up internet connections
    • Hide the IP address of the client computer
    • Enforce internet access control
    • Scan content be sent by the local computer

    SNMP Services

    Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically support SNMP include cable modems, routers, switches, servers, workstations, printers, and more.

    SNMP is widely used in network management for network monitoring. SNMP exposes management data in the form of variables on the managed systems organized in a management information base (MIB) which describe the system status and configuration. These variables can then be remotely queried (and, in some circumstances, manipulated) by managing applications.

    Adapted from:
    "Network Time Protocol" by Multiple ContributorsWikipedia is licensed under CC BY-SA 3.0
    "Introduction to the Domain Name System (DNS)" by David Both, OpenSource.com is licensed under CC BY-SA 4.0
    "Simple Network Management Protocol" by Multiple ContributorsWikipedia is licensed under CC BY-SA 3.0

    • Was this article helpful?