Why do you need an IP address if you have a poppy address? Those. remove level 3 of the OSI model (routing) and do all the switching. Or, on the contrary, remove level 2 and leave only 3.

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    Some programs work the same way. By MAC addresses. But within the same LAN segment. In general - RTFM. - alexlz
  • @qpeela, If you are given an exhaustive answer, mark it as correct (click on the check mark next to the selected answer). - Vitalina

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

Remove the 2nd level just does 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 mac addresses). Those. we are then forced to announce a separate address instead of the network announcement, this time, we can do ipv6 in general like this: ourn: etad: dres: fe80 :: pcma: cadd: ress, but this will require changing the entire infrastructure, moreover, will not save us from the ethernet protocol, but simply hide it. True, locally, in your segment, of course, you will be able to issue ipv6 addresses via dhcp, based on the mac address, no one will hurt you :)

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

  • @eicto Communication can be arranged by arp <boring-mode> An interesting phrase. Imagination overstrains ... And ischo. The ip-address does not belong to the computer, but to the interface. Host ip-address does not have ... </ bore-mode> - alexlz
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    <ultra-зануда-mode> not the interface it belongs to but the network, in the sense that the interface is an optional abstraction in terms of tcp / ip, for example, using iproute and such a mother, I can probably make sure that all interfaces have same ip and at the same time that it worked. Well, or in general, in imagination - a kind of software and hardware complex, in which the OS will not know about physical interfaces at all. (By the way, programs usually don’t know about interfaces, but use the ip network) </ultra-зануда-mode> strange? How long can I write arp-chat? - zb '
  • Of course in arp you can arrange communication, but you are right - it will be something like ip over icmp - zb '
  • > How long can I write arp-chat? Describe the algorithm of work, and I will most likely explain to you why this cannot be called “arp-chat”. For reference, ARP is the Address Resolution Protocol, a protocol that allows (within one L2 segment) to determine which MAC address (L2 address) has an interface on which the desired IP address is raised. - MrClon
  • in my youth, such a poster was about mysoftware.ru/download/setevoy_plakat_karti_protokolov :) for some reason I somehow got it free then, - zb '

Previously, there was no single standard for equipment, in particular, for physical addressing. It was necessary to introduce a common standard for interconnection between networks, which would be understandable to all devices. So IP appeared. Many people call it the Internet Protocol, but the Internet Protocol is correct.

  • IP is primarily a protocol for solving the problem of traffic routing. The unification of heterogeneous networks is perhaps the second time. Layer 2 protocols do not work well in large distributed networks. - MrClon
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    RIP, OSPF are engaged in routing. An IP is a wrapper containing simply the addresses of the sender and recipient. But what route it will take, IP does not regulate. - aleksandr_mai
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    @aleksandr_mai, read on "routable protocols" and "routing protocols". If static routing is static, then no RIP-NEXT may be required. And besides, these routing protocols are for small networks. - alexlz
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    @aleksandr_mai, dynamic routing protocols (RIP, OSPF, EIGRP, and other BGP) are essentially just tools to automate the routing table. For the routing itself is responsible IP. The IP protocol is not only an IP packet, it is also the rules for handling it. - MrClon
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    @aleksandr_mai some more bore. Is the router a device or program (for example, a router on a personal computer)? A static table fills the man. So what? - alexlz

I recommend to read this lecture. In it the organization of networks is considered from the point of view of solved tasks. How to recreate the process of developing network protocols. Very interesting, in my opinion.

https://tech.yandex.ru/education/kit/3/talks/526/

https://tech.yandex.ru/education/kit/3/talks/527/

  • @MrClon, it is impossible to insert a comment there, apparently brute force. Here's to drive an aspen stake, I will quote from the IP standard (RFC 791): clause 1.4. We read ... "The internet protocol implements two basic functions: addressing and fragmentation". - aleksandr_mai
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    @aleksandr_mai, the addressing problem is solved in the L2 protocols. But sane routing there and does not smell, since there is no summation of addresses. - MrClon
  • @MrClon, to be fair, there are ways of routing channel protocols, recall the same bridges over open-vpn or switches that make up the mac-address table on their interfaces (what is not routing?). Another thing is that it is not very convenient for large networks and it will be terrible to fail where the hierarchy of physical links is not a tree. - zb '
  • @MrClon, so what is the arp protocol itself (without any over the top) not communication between network members? Information is passed between participants? Is the protocol observed? Did one node get information about another? I have no doubt that you are right, just to be strictly, then to the end. And the problem of creating protocols is not to come up with them, but rather to be supported by someone other than the one who came up with (ipx, for example, he, by the way, is a bit like what I described as an agreement ipv6). - zb '
  • @eicto, I do not think that what is on L2 can be called routing. Rather, "everyone knows everyone." In the proposed embodiment, all the switching lies entirely on L2, and ARP is inserted between the payload and L2, the devil knows why. Actually no longer stick, as I can see. “Communication can be arranged via ethernet too”, I am happy. - MrClon