[ntp:questions] forwarding

Brad Knowles brad at stop.mail-abuse.org
Sun Mar 13 14:11:15 UTC 2005

At 6:13 AM +0000 2005-03-13, Wolfgang S. Rupprecht wrote:

>  Loops are certainly an important concern, but traditionally they were
>  dealt with by the gateway injecting a gateway-specific header such as
>  "X-Loop: XXXX".

	The problem is that some gateways strip what they consider to be 
unnecessary headers, and certainly our gateway would not recognize 
the "X-Loop:" header that may have been added by another gateway, nor 
would they recognize ours.

	Unfortunately, we cannot guarantee that there is one and only one 
bi-directional gateway.  Given the history of such systems, we have 
to assume that we have to protect ourselves, our subscribers, and all 
the readers of the newsgroup against situations where a rogue gateway 
causes our normally-good gateway to operate in a manner that is 
highly destructive.

>  My newsreader (Gnus v5.10.6) uses the "References:" header to walk up
>  the thread.  It asks the nntp server (in my case news.sonic.net) to
>  hand it the articles with the mentioned Message-Id's.  Are you saying
>  that mailman expects it to do something differently?

	It should be able to fill in the missing details by looking at 
all the articles that are referenced.  My understanding is that the 
Zawinksi algorithm does this.  The fact that a particular article 
doesn't exist on the server should not prevent it from being able to 
fill in the rest of the details.  It should be able to infer the 
correct thread positioning based on incomplete data.

Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.

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