Unit 1: Network Infrastructure
This will allow you to demonstrate your networking skills, knowledge, and abilities, with a focus on enterprise-level switching, routing, and multicast components that support cross-platform (inter)operability and integration with the most recent software-defined technologies.
The Frame for Ethernet
To put it another way, a frame is the same thing as a data packet or a data unit. The frame is the Protocol Data Unit, or PDU, at the Data link layer in the Open Systems Interconnection (OSI) Model. We can see what an Ethernet Frame looks like by looking at the image that is provided below:
Let us talk about the Fields in more detail:
In its most basic form, the Preamble is a piece of information that notifies the receiving node that a frame is on its way and states the beginning point of the frame. It is not a component of the Ethernet frame; rather, it is a component that assists in the transmission and reception of Ethernet frames without any collisions or errors!
Due to the fact that the Ethernet Frame encapsulates the protocol that transports the Packet inside (the Data field), the Type field is a message that is sent to the network layer in order to identify the type of protocol that will be utilized.
- 0x0800 = IPv4
- 0X86DD = IPv6
- 0x0806 = ARP
- 0x8100 = dot1q (VLAN Tag)
The payload that the frame holds, like an IP packet, is stored in the Data field. Ethernet frames can only hold 1500 bytes.
Frame Check Sequence (FCS) is what the FCS field stands for, and it checks for errors. Using a Cyclical Redundancy Check (CRC) for the hash, which is used to check for errors.
