[NNTP] LIST EXTENSIONS (again)

[Mark Crispin]

On Fri, 5 Nov 2004, Russ Allbery wrote:
> Hm.  That strikes me as odd -- how does an NNTPv2 client know if a server
> advertising NNTPv3 is okay or not?

The server must advertise both NNTPv2 and NNTPv3.  A server which just 
advertises NNTPv3 is not OK to an NNTPv2 client.

This will place a chilling effect on any effort to create NNTPv3, perhaps 
permanently preventing it.  Good.

>> I'm probably not qualified to answer this, but might there be a case
>> where "lightweight" reading is offered for free (w/o authentication),
>> but more "expensive" commands such as NEWNEWS or OVER or some future
>> XSEARCH are only allowed to (paying) customers that authenticate?
> Yeah, but in that case, wouldn't you advertise the extensions but reply
> with a 480 code to attempts to use them, prompting the client to
> authenticate?  That was what I'd been assuming in previous discussions of
> extension advertisements, but maybe that's not the best way to do it?

I think that it's better to move away from magic response codes and use 
extensions exclusively.  The fact that authentication is offered is enough 
of a hint to anonymous clients that more can be gained through 
authentication.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.