https://www.rfc-editor.org/rfc/rfc9000.html#section-9-2 says that during the handshake the endpoint addresses must remain stable. There are some exceptions to this: the preferred_address transport parameter and iroh's special case that allows the server to migrate while no authenticated Handshake packet is received by the client.
However the current code does not really enforce that migration doesn't happen during the handshake. The packets triggering client migration are not ignored.
https://www.rfc-editor.org/rfc/rfc9000.html#section-9-2 says that during the handshake the endpoint addresses must remain stable. There are some exceptions to this: the preferred_address transport parameter and iroh's special case that allows the server to migrate while no authenticated Handshake packet is received by the client.
However the current code does not really enforce that migration doesn't happen during the handshake. The packets triggering client migration are not ignored.