computer networking protocols explained
The definition of the word protocol is an agreement on how something is done. There are many types of protocols. Business ones and social ones but here we talk about networking protocols, which means defined the rules of communication between devices.
We can classify protocols like routed protocols and routing protocols.
Routed protocol is a networking protocols that is capable of being routed, this means that the protocol was designed for transferring information to networks other than the network in which the source device resides.
Obtains and uses the information require to route the packets of the routed protocol.
Configuring routes from the command line is called static routing. And we can find protocols in each layer of the networking model.
Exploring application layer protocols
Protocols that operate at the application layer are dedicated to a very specific function. For example, DNS, Which gets its name from the hierarchical system that its uses called Domain Name System. This protocol does nothing but handle request from computer that are trying to match an IP address with a computer name.
FTP stands for file transfer protocol is a connection oriented protocol dedicated to moving files from one computer to another. It operates on a client server model, which means that the FTP client application is used to request the data, and the FTP server will respond and send the data.
Trivial file transfer protocol is the connectionless version of FTP. TFTP has a very limited set of capabilities and provides no aunthentication.
It is designed to be lightweight and fast, and so it uses UDP as its transport protocol.
Although it not the only protocol involved in sending and receiving of email, simple mail transfer protocol (SMTP) is the internet standard used when email is transferred from one server to another server.
SMTP use TCP port 25 so it is connection oriented and thus benefits from all of the features and overhead of TCP.
If DNS did not exist, we could not connect to websites on the internet or other computer on a LAN without knowing the IP address of the computer hosting the website or the IP address of the computer on the LAN.
DNS perform resolution of an IP address to a computer name or website name. It operates in a hierarchical arrangement known as DNS namespace.
There are three levels to this hierarchy:
- root level
- top level
- domain level
Each computer is configured with the address of the DNS server. This IP address can be either configured statically or provided automatically from a DHCP server.
Simple network management protocol; is an application layer protocol used to manage and monitor devices on a network from a central location. These devices can include computers, routers, switches, wireless access points and more.
Transport Layer Protocols
The transport layer is responsible for identifying the application layer protocol to the destination computer. It does this by using what are called port numbers.
UDP is used for broadcast and multicast transmissions, and TCP is used for unicast transmission.
Internet layer protocols
This is the layer where routing occurs and where the resolution of IP address to MAC addresses occurs. And there are two protocols found in this layer ICMP and IGMP.
Internet protocol is a connectionless protocol that depends on TCP when connection-oriented operations are required. The IP header is attached to the segment containing everything was added at the application and transport layers, this container is called an IP datagram or packet. It is capable of being routed because it is labeled with IP address information.
Address resolution protocol is responsible for resolving the IP address to the MAC address of the destination.
Internet group management protocol; this protocol is used for multicasting, the protocol operates between routers and host that belong to what are called multicast groups.
Network access layer
Protocols of the network access layer can be categorized as either LAN protocols or WAN protocols; these protocols use some sort of information to identify the individual hosts in a LAN and to identify the endpoints in a WAN.