Why do you need an IP address if there is a MAC address?

Question:

Why do you need an IP address if there is a poppy address? Those. remove layer 3 of the OSI model (routing) and do everything by switching. Or vice versa, remove level 2 and leave only 3.

Answer:

Communication can also be arranged via ethernet, the fact is that most programs work with the tcp / ip protocol, since this is more universal. If you want to arrange switching for the entire Internet, then you will be disappointed – imagine how much noise there will be in such a network, because without routing, all packets sent by someone will come to all network members (even if you do something like switches, (which will determine on which port which mac), then this will require, firstly, just the craziest tables of poppies by port, and secondly, the network is not a hierarchical structure, i.e. there are no guarantees that the outgoing packet will arrive only one port.In general, read about the device of the ethernet protocol.

Removing the 2nd level simply will not work, because. in this case, you will have to announce each address separately (say, we say – now ipv6 is fe80:: and then we calculate from the mac address). Those. in this case, we are forced to announce a separate address instead of announcing the network, this time, we can generally do ipv6 like this: ourn:etad:dres:fe80::pcma:cadd:ress, but this will require changing the entire infrastructure, in addition, will not get rid of the ethernet protocol, but simply hide it. True, locally, in your segment, of course, you can issue ipv6 addresses via dhcp, based on mac address, no one will bother you 🙂

And there are also networks in which there is no mac-address, but there is ip 🙂 They are called point-to-point (for example, when we connect via modem, there is no ethernet protocol).

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