Ethernet Header Example

Ether Type Field The EtherType field in the Ethernet frame header identifies the protocol carried in the payload of the frame. For example, a value of 0x0800 indicates that the payload is an IP packet, while a value of 0x0806 indicates that the payload is an ARP Address Resolution Protocol packet.

Each Ethernet frame starts with an Ethernet header, which contains destination and source MAC addresses as its first two fields. The middle section of the frame is payload data including any headers for other protocols for example, Internet Protocol carried in the frame. The frame ends with a frame check sequence

For example if you are using Ethernet IEEE 802.1, the Half-Duplex bandwidth is 10 Mbps and the Full-Duplex bandwith is 20 Mbps. Here, it will be useful to talk about a key differece between Ethernet II and IEEE 802.3 Frame Header. In the Ethernet II, there is a

Example 3 Ethernet Frame with Q-in-Q Double VLAN Tagging, 802.1ad Q-in-Q allows for nesting of VLAN tags, creating a hierarchy of VLANs is the Ethernet header length with VLAN tag 18 bytes

Following image shows the Header, Data and Trailer part of Ethernet Frame. Ethernet Frame fields An example representation of MAC address is AA.F0.C1.E8.13.40. To view the MAC Address when you are working with a Windows workstation, run cmd Start gt run gt type cmd and Enter. Type the command quotipconfig allquot in the prompt and Enter.

And so, as Ethernet components process each packet, they will make references to, for example, IP at upper layers by using the fields in the frame header. CSMACD. At this point, we know that Ethernet is a layer 2 protocol, which provides among other things addressing to a MAC address but also an access method.

Ethernet format. An Ethernet frame contains three parts an Ethernet header Preamble, SFD, Destination, Source, and Type, Encapsulated data Data and Pad, and an Ethernet trailer FCS. The following image shows an example of an Ethernet frame.

Of course, big manufacturers need many more addresses, and thus they are assigned additional OUIs. For example, 000164 is another OUI that belongs to Cisco. Unicast and Multicast Bits. Ethernet addresses also consist of two special bits. The first special bit indicates whether the address is a unicast or a multicast address.

An Ethernet frame starts with a header, which contains the source and destination MAC addresses, among other data. The middle part of the frame is the actual data. The frame ends with a field called Frame Check Sequence FCS. The Ethernet frame structure is defined in the IEEE 802.3 standard.

The Ethernet header is composed of the following fields, as seen below Preamble this is a 7-byte pattern of ones and zeroes and is used for synchronization. Data this carries the actual data that we are trying to transmit, for example an IPv4 packet. FCS the frame check sequence helps the receiver to figure out if the frame is correct