Today, many organisations still use it to manage IT access, by letting in all whitelisted MAC addresses while keeping out the ones that aren’t. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.When you’re an IT manager, you’ve probably heard of MAC address filtering. Have something to add to the explanation? Sound off in the comments. Make sure to read through the rest of the lively discussion thread via the link below! While there is nothing directly preventing the creation of a protocol that encompasses both Layers 2 and 3, it would be less flexible, less attractive, and therefore unlikely to be used. Equally, IP can be swapped out for different network layer protocols (provided it happens for all participants) such as Asynchronous Transfer Mode (ATM). IP does not care what the underlying layer is. In the real world there are different data link protocols that you are already using (although their addressing schemes are the same): 802.3 – Ethernet, and 802.11 – Wi-Fi. Clearly this would not be particularly fast, but it would still be IP provided the person carrying around the bits of paper respected IP routing rules. For example, you may choose to connect to your Internet service using IP over Ethernet, but in your internal network, you might choose to use IP over paper (where someone writes down the contents of each packet and physically walks it over to another machine and types it in). Neither is reliant on the other, which is what gives networking its flexibility. Ethernet specifies a family of technologies that allow packets to be sent and received between network devices, whereas IP defines a protocol that allows packets of data to traverse multiple networks. ![]() The requirements for each of these layers is different. Layer 2 in this scenario is Ethernet – from which MAC addresses arise, and Layer 3 is IP.Įthernet only works at the local level between network devices connected to a broadcast network “data link”, whereas IP is a routable protocol and can target devices on remote networks. The two layers you are talking about here are Layers 2 and 3. The different network layers are there to allow them to be swapped for different technologies. SuperUser contributor Paul has the answer for us: Why is there a need for Ethernet/MAC addresses? The Answer My other question is: Why are IP addresses needed if all devices have unique MAC addresses? X.1 sends a packet to all computers in the network and only X.2 will process it, the others will ignore it.It would be simpler to just do it in one step: X.1 gets a MAC address and sends the packet.To do so, X.1 needs to send a packet to all computers in the network and only one will answer.X.1 uses ARP to get the MAC address of X.2.A computer with the IP address 192.168.1.1 (X.1) wants to send a packet to the address 192.168.1.2 (X.2). ![]() ![]() Surely all computers could just be connected to a unified network and use IP addresses to communicate?įor example, there is the following mechanism in Ethernet: I do not understand why Ethernet/MAC addresses are needed. SuperUser reader user2449761 wants to know more about the need for Ethernet/MAC addresses:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |