On Fri, Mar 31, 2023, at 12:12, Marcin Nawrocki wrote: > Do we really need to pad all server initial packets to 1200 bytes?
Technically, no. There are a number of places in the handshake where padded Initial packets do not provide any of the features we rely on them providing (seeding anti-amplification limits, path MTU detection). However, as a practical matter, some implementations will not process Initial packets when the UDP datagram that carries them is less than 1200 bytes in size. They are thrown out unconditionally. The lesson: we should have been more careful about how we specified the requirements around Initial packet/datagram size.
