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i completely understand that why receiver there is 576 bytes but my question is as technology update every after one Minutes then why we can't update that limit

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  • I think you accidentally deleted your link - could you please re-add it? The question makes no sense as it now is. Sep 24, 2021 at 14:20
  • Did any answer help you? if so, you should accept the answer so that the question does not keep popping up forever, looking for an answer. Alternatively, you could post and accept your own answer.
    – Ron Maupin
    Dec 23, 2021 at 22:10

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i completely understand that why receiver there is 576 bytes but my question is as technology update every after one Minutes then why we can't update that limit

You fundamentally underestimate how hard it is to make a backwards-incompatible change to the Internet.

If you make a backwards-incompatible change to the Internet, EVERY SINGLE DEVICE ON THE INTERNET MUST BE UPDATED AT THE SAME TIME. This means every cellphone, every tablet, every laptop, every desktop, every server, every smartwatch, every smart TV, every smart fridge, every smart lightswitch, every smart speaker, every Wireless AP, every broadband router, all hundreds of thousands of servers of Google, all hundreds of thousands of servers of Microsoft, all hundreds of thousands of servers of Amazon, and so on and so forth. And that's not talking about all the embedded devices, industrial devices, edge devices, etc.

But even more importantly, all the routers, all the proxies, all the DNS servers, all the web servers, all the load balancers, all the mail servers, all the file servers, all the streaming servers, all the firewalls, all the VPNs, in short, the entire fundamental infrastructure of the Internet, they also all need to be updated at the same time.

Before this can happen, every single Operating System vendor, from Microsoft to Apple to IBM to HP to WindRiver to VxWorks, all the open source communities, Linux, FreeBSD, NetBSD, OpenBSD, DragonflyBSD, ReactOS, all the big mainstream OSs, all the realtime OSs, all the embedded OSs, all the niche OSs, but also the switch and router operating systems, Arista EOS, Cisco NX-OS, Cisco IOS, Juniper, HP, and so on, they all need to update their Operating Systems.

This is simply unrealistic.

You can only do this by introducing a new protocol and migrating step-by-step from the old to the new. This is actually what happens with IPv6: it does increase the minimum MTU (and the address size, and changes a whole bunch of other things). It was developed in the 1990s and standardized in 1998, 23 years ago. It is only now starting to get serious traction, and only in limited areas. E.g. mobile Internet is mostly IPv6, but home installation and offices, for example, are still almost exclusively IPv4. In the industry I work in, even products that are being newly developed right now, often don't even support IPv6 at all.

In fact, in the industry I work in, 576 octets is already too big anyway for many applications, so why would we care about raising that limit?

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You cannot change IPv4's minimum MTU requirement because changing a fundamental requirement will break the Internet.

Specifications exist so that any device design can be fully functional in any network. Imagine an industrial network where one components breaks or needs to be upgraded. The new component's changed specifications don't comply with the rest of the network any more and may cause any kind of problems - perhaps not even right away but on a weekend, somewhere in the future...

IPv6 did change the minimum required MTU to 1280 bytes. That is possible because IPv6 is a separate network-layer protocol, requiring new implementations anyway.

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