Ethernet, unlike, say, Infiniband, doesn't promise things will get where you sent them just because it didn't error initially, so other protocols handle this at

Ethernet, unlike, say, Infiniband, doesn't promise things will get where you sent them just because it didn't error initially, so other protocols handle this at higher levels to notice the failure cases.* For an example of what this means, try setting your MTU above the limit, and watch the raw traffic. * - it's been years since I cared about the formal definition, my apologies if I got it wrong.