From: Bryan Reece <reece@taz.nceye.net>
To: “E. Allen Smith” <EALLENSMITH@ocelot.Rutgers.EDU>
Message Hash: 47ae1eee272139d2791af40e7833cb2ec9e55d00a0ba71908469682ec581f0a6
Message ID: <19970218141819.28530.qmail@taz.nceye.net>
Reply To: <01IFJH1ONXA88Y4YVV@mbcl.rutgers.edu>
UTC Datetime: 1997-02-18 14:18:02 UTC
Raw Date: Tue, 18 Feb 1997 06:18:02 -0800 (PST)
From: Bryan Reece <reece@taz.nceye.net>
Date: Tue, 18 Feb 1997 06:18:02 -0800 (PST)
To: "E. Allen Smith" <EALLENSMITH@ocelot.Rutgers.EDU>
Subject: Re: Anyone have the complete info on CP list alternatives?
In-Reply-To: <01IFJH1ONXA88Y4YVV@mbcl.rutgers.edu>
Message-ID: <19970218141819.28530.qmail@taz.nceye.net>
MIME-Version: 1.0
Content-Type: text/plain
E. Allen Smith writes:
> From: IN%"reece@taz.nceye.net" "Bryan Reece" 17-FEB-1997 23:23:10.06
>
> >> use. However, I do have one problem with this recipe: lack of
> >> loop prevention if a news2mail gateway is going in the other direction.
>
> >All the mailing-list hosts are supposed to check for duplicates before
> >forwarding anything, so this shouldn't do anything worse than have a
> >few extra copies of each post get discarded, loading the network and
> >the hosts a bit more. But posting the list to a widely-distributed
>
> Umm... IIRC, the only person who's announced how he's filtering
> for duplicates is Igor, and he's just checking for messageIDs. Won't
> those get chunked on going through a mail2news gateway, and thus
> possibly come back through a news2mail gateway?
My script preserves the Message-ID, assuming that the incoming message
has one. Other gateways I've seen also appear to preserve Message-ID
lines (or at least messages posted through them appear to have
mail-like ID lines).
> The filtering
> mechanism could be improved via MD5 digests, etcetera (someone's
> already given a recipe for such; thank you), but even so various
> mungings could still set up a mailing loop. (Yes, I'm paranoid
> about those; I may have been reading list-managers for too long and
> seen too many stories on there.) The sensible place to keep
> track of possible duplicates is at the gateway; it can
> certainly filter based on that it (or, for that matter, another
> known bidirectional gateway) sent a message out.
Not immediately sending a message back to the host that it came from
does look like a good idea (it came from foo.com, so foo.com obviously
has it). Filtering out other gateways' messages will reduce load at
the possible expense of delay (assuming a smallish network of news
servers that feed each other the list; obviously the message will
flood the majordomo net before it floods the real usenet unless
something is seriously broken).
>
> >newsgroup seems wrong for noise (both to the list itself and to
> >posters) and delay reasons.
>
> Delay reasons being that mail will go to Usenet, go
> all over the place there, and then get replied to later than if
> it were just on the mailing list(s)? A potential problem, yes.
I didn't exactly say, but I was comparing a small network of news
servers feeding each other cypherpunks.list to, say,
alt.cypherpunks.list.
> But (especially given the options I mentioned below), this
> would appear to be a matter for individual users to decide
> by which list they go with and any added control headers.
I'm trying to come up with a way to provide NNTP access (and an
experimental alternative to the net-of-majordomos) that won't offend
anybody too much. I can filter out messages that the authors don't
want sent out; I'd prefer to deal with what would make the authors
want the messages filtered out instead.
> Maximum individual sovreignty (sp?).
>
> >> In regards to your later query about whether people want their postings
> >> going to Usenet, might I suggest that this be individual to the given
> >> distributed mailing list? In other words, since the recipe is logically
> >> going to have to not forward to a gateway messages from other mailing
> >> lists (since it's not a good idea to have multiple copies of the same
> >> message arriving at the gateway if it can be helped; better to filter
> >> it out beforehand),
>
> >It doesn't seem an especially bad idea, since it
>
> Thank you. Were you cut off?
Yes. Should have read:
It doesn't seem an especially bad idea to send a gateway multiple
copies of the same message, since theextra messages won't increase the
load much but will increase the reliability and decrease the
propagation time compared to a network where there are no duplicates.
The only case where filtering duplicates is certain not to hurt delay
or reliability is when the gateway in question is known to have a copy
of the message already. Usenet uses the Path header for this; there
doesn't seem to be such a thing in the majordomo net.
> >> some of the mailing lists can forward and the
> >> others cannot. (One could even determine this behavior on application
> >> of the proper X-header, although I never trust various mailing systems
> >> to forward such intact.) The same could also be done with gatewaying
> >> _from_ Usenet - if the news2mail gateway feeds to whatever individual
> >> lists sign up to it and they _don't_ forward such messages to others,
> >> people can decide whether or not to receive Usenet postings on
> >> alt.cypherpunks.* by which list they subscribe to.
>
> >The code currently running is a perl script that turns typical email
> >messages into something INN is happy with. It is probably possible to
> >get your message rejected by INN if you put obsolete or otherwise
> >unusual and illegal headers in. This may be a bug.
>
> That would probably depend on: A. if any other circumstances
> other than deliberately sabotaging your message's translation would
> also disrupt its chances of getting through seriously, particularly
> if they weren't something you'd spot; and
The main way to get a message rejected seems to be using obsolete
news headers on it. If you don't want your message posted, add a
Posting-Version line to the header.
> B. if sufficiently bad
> messages would disrupt INN's operations too much.
No more so than a sufficiently bad news posting that came in over NNTP
(since the mails do turn into news postings over NNTP).
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