Getty Images

5 common network services and their functions

DHCP, DNS, NTP, 802.1x, and CDP and LLDP are some of the most common services network administrators use to secure, troubleshoot and manage enterprise networks.

Network services are utility applications that help extend the capabilities, management and security of enterprise networks.

Network pros often use services to eliminate many complexities found in large networks. Network service tools help administrators facilitate network access to applications and resources, while also providing visibility to aid in troubleshooting and network authorization or access.

Common network services include the following:

  • Dynamic Host Configuration Protocol (DHCP).
  • Domain name system (DNS).
  • Network Time Protocol (NTP).
  • IEEE 802.1X.
  • Cisco Discovery Protocol (CDP) and Link Layer Discovery Protocol (LLDP).

Here, we provide an overview of these network services and how network administrators use them.

1. Dynamic Host Configuration Protocol

Devices require a configured IP address to connect and communicate on IP networks. This includes a unique IP address -- either IPv4 or IPv6 -- a subnet mask and default gateway. Network pros can deploy a DHCP server on the network to help facilitate the configuration of IP address information, along with other important network services, like DNS.

DHCP is a protocol that assigns IP addresses to network devices. Network pros can then set endpoint devices to dynamically contact the remote DHCP server and request address information. This ensures the network places endpoints into the appropriate IP subnet and avoids issues like IP address conflicts.

2. Domain name system

A DNS server translates domain names that are easily understood and remembered by humans into the IP address of a remote application or server location. For example, when a user types the domain into a web browser, a DNS server translates it to the IPv4 or IPv6 address of the server where the website is hosted.

DNS uses caching to store previous queries and answers, which results in faster response times in the future. Data can be cached in a system browser and OS.

3. Network Time Protocol

NTP is a protocol that synchronizes clocks on computer systems. When network professionals troubleshoot network health and performance problems or investigate security incidents, it's important that they ensure the network and other infrastructure equipment have precise and synchronized time configured. Network pros can use NTP servers to create a centralized source for clock synchronization for IT infrastructure components.

4. 802.1X

The 802.1X standard enables network access control and authentication for LANs and wireless LANs. For security purposes, it's important that users and devices authenticate their identity before they gain access to an enterprise network. 802.1X is a commonly deployed network service protocol that requires users or autonomous devices to successfully authenticate using some form of unique credentials before accessing the network.

5. Cisco Discovery Protocol and Link Layer Data Protocol

CDP is a protocol that discovers Cisco devices and collects device information, such as hardware type, protocols and software versions. LLDP is a vendor-neutral discovery protocol that enables neighboring network devices to send and receive information, such as IP and MAC addresses, port descriptions, protocol IDs and time to live, among other items.

Network administrators commonly use CDP and LLDP network services to identify network-connected devices that support one or both protocols. This information can help network professionals map and visualize the network and connected devices for management and troubleshooting purposes.

Next Steps

How a DDI platform supports IP-based network management

Dig Deeper on Network management and monitoring

Unified Communications
Mobile Computing
Data Center