Network Services

Domain Name System

• Used to translate domain names into IP addresses.

• Web servers are identified by IP address. DNS allows us to type in a text address& converts it to the correct IP address.

• We can also use DNS on our private network to assign names to the domains and subdomains.

Directory Services

• Used to organise information on network objects such as users & computers.

• Makes the information easily accessible for centralised administration, authorisation & authentication.

• Runs on the domain controller.

• Example directory services include:
• Active Directory
• Open Directory
• OpenLDAP

Authentication Services

• Provides username/password login authentication.

• When a user wants to connect a device to a network they will need to first authenticate themselves.

• This prevents connecting unauthorised devices by malicious users.

• Can also allow for users to connect to the network domain from outside the organisation.

Dynamic Host Configuration Protocol

• A protocol that is used to automatically assign IP addresses to the different devices connected to a network.

• Also allows centralised management of IPs.

• Helps to prevent clashes in IP addresses and to use a smaller number of addresses.

Routing

• The process of directing data packets between multiple networks to reach its destination.

• Performed using routing tables which each router maintains.

• Routers receive packets & find recipient address in header.

• This allows them to look up the address in their routing table & identify the IP of the next gateway to move the packet towards its destination.

Remote Access Services

• Provide access to a network from outside the organisation.

• The network will setup a remote access server, which the user will need to authenticate itself with in order to access network resources.

• Often will come with VPN features to allow secure transmission.

File & Print Services

• File servers are used for the centralised storage & management of files so they can be accessed by clients over a network.
• Access rights are managed through directory services.

• Print servers provide access to printers to client devices over the network.
• The print server will also make the print queue available to the clients.

Web, Mail & Communication Services

• Web servers are used for the storage and access of web pages and their relates files to users.

• Mail servers provide the ability to send and receive emails over a network.

• Communication servers are used to provide internet access to all the clients on a network.