Could you do the same with a 1501 byte packet?
> On Mar 9, 2016, at 10:51 AM, Nick Hilliard <n...@foobar.org> wrote: > > Kurt Kraut wrote: >> Thank you for replying so quickly. I don't see why the consensus for an >> MTU must be reached. IPv6 Path MTU Discovery would handle it by itself, >> wouldn't it? If one participant supports 9k and another 4k, the traffic >> between them would be at 4k with no manual intervention. If to >> participants adopts 9k, hooray, it will be 9k thanks do PMTUD. >> >> Am I missing something? > > for starters, if you send a 9001 byte packet to a router which has its > interface MTU configured to be 9000 bytes, the packet will be > blackholed, not rejected with a PTB. > > Even if it weren't, how many icmp PTB packets per second would a router > be happy to generate before rate limiters kicked in? Once someone > malicious works that out, they can send that number of crafted packets > per second through the IXP, thereby creating a denial of service situation. > > There are many other problems, such as pmtud not working properly in the > general case. > > Nick >
