Cisco Certification – The OSI Model
The normal model for networking protocols and distributed software is that the International Standard Organization’s Open System Interconnect (ISO/OSI) version. It defines seven network layers.
Short for Open System Interconnection, an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. Control is passed from 1 layer into another, beginning at the application layer in 1 station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.Visit here https://examreactor.com/
At once, most vendors agreed to support OSI in 1 form or another, but OSI was too loosely defined and proprietary standards were too entrenched. Except for its OSI-compliant X.400 and X.500 email and directory standards, which are frequently employed, what was thought to be the universal communications standard now serves as the teaching model for the other protocols.
Control is passed from 1 layer into another, beginning at the application layer in 1 station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.
Layer 1 – Physical
Physical layer defines the cable or physical medium itself, e.g., thinnet, thicknet, unshielded twisted pairs (UTP). All websites are equal. The most important distinction is in cost and convenience of maintenance and installation. Converters from one press to another function at this level.
Layer 2 – Info
LinkData Link layer defines the arrangement of information on the system. Aka packet, A network data framework, comprises information, and source, checksum and destination address. The largest packet which may be transmitted via a data link layer defines the Maximum Transmission Unit (MTU). The data link layer manages the logical and physical links to the destination of the packet . A server could have connections to be handled by an Ethernet port and a loopback interface to send packets.
Ethernet handles a server with a distinctive, 48-bit address known as its Ethernet address or Media Access Control (MAC) address. MAC addresses are often represented as six colon-separated pairs of hex digits, e.g., 8:0:20:11:ac:85. This number is unique and is connected with a certain Ethernet device. The exact same address should be used by hosts with multiple network interfaces . The protocolspecific header of the data link layer defines the address of the destination and source of the packet. When a package is delivered to all hosts (broadcast), a particular MAC address (ff:ff:ff:ff:ff:ff) is utilized.