>I feel like the last piece we’re missing in this story is the performance impact of fragmentation. Like why not just set all new hardware to an MTU of 9000 and

>I feel like the last piece we’re missing in this story is the performance impact of fragmentation. Like why not just set all new hardware to an MTU of 9000 and wait ten years? Because a node with a MTU of 9000 will very likely be unable to determine the MTU of every link in it's path. At best, you'll see fragmentation. At worst, the node's packets will be registered as interface errors when it encounters an interface lower than 9k. Neither of those are desirable.