Re: hotmail not dealing with ECN

Alan Cox
2001-01-31T10:46:46Z

> > RFC793, where is lists the unused flag bits as "reserved".
> > That is pretty clear to me. It just has to say that
> > they are reserved, and that is what it does.
> >
>
> Is the definition of "reserved" defined anywhere? In a lot of specs,
> "reserved" means MBZ.
>
> Note, that I'm not arguing with you. I'm trying to pick this apart.

Reserved values are normally (as in 793) listed as reserved, must be zero.
The meaning of that in RFC literature is absolutely clear. That in the absence
of you supporting a newer feature using these bits the value must be set to
zero. You may not rely on it being zero from another host however.