5 ms·
In my utopic world, we wouldn't need "ICMP won't fragment". IPv4/IPv6 would have the MTU of exactly 4096 bytes. Why not a higher or lower level protocol? Becau
by anticristi 5y ago
In my utopic world, we wouldn't need "ICMP won't fragment". IPv4/IPv6 would have the MTU of exactly 4096 bytes.
Why not a higher or lower level protocol? Because this is the lowest level protocol which is end-to-end and has a path MTU. Lower level protocols would need to somehow handle the MTU and higher level protocols would need to fit their segments within the MTU.
Why 4096? Because this is a common page size on computers. Multiple of this would likely bring little benefits, due to GRO/GSO.
Also, it's my utopic world, so if you don't like it create your own. :))
- zamadatix 5y agoNot much of a utopia if all you do is say the same problem is now unsolved at a different layer ;). Nothing special about the layer below IP that allows it to fix the problem in a way IP couldn't be made to - it's just an annoying problem to fix efficiently.
- alerighi 5y ago4096 can be too much for unstable connections, for example Wi-Fi or mobile. Also, 4096 bytes at what level? Layer 2? And when you are using a tunnel, you add bytes and thus have to go higher than 4096 or go lower and reduce MTU, or fragment the packet to keep 4096 bytes. You are just raising the limit, not solving the problem.
- tinus_hn 5y agoThis is the network version of ‘640k should be enough for anyone’. Don’t fixate this kind of policy in such a fundamental protocol.
- noselasd 5y agoThe issue is how the network are glued together, your X MTU will be embedded in a VPN tunnel, PPPOE - and that device needs to tell your device about its MTU
- AlphaSite 5y agoHow would this work for IP over IP networks?