TCP/IP Guide

NNTP Interserver Communication Process: News Article Propagation

To understand how NNTP propagation works, we must begin with a look at the way that the modern Usenet network itself is organized. Usenet sites are now all on the Internet, and theoretically, any NNTP server can contact any other to send and receive Usenet articles. However, it would be ridiculous to have a new article submitted to a particular server need to be sent via separate NNTP connections to each and every other NNTP server. For this reason, the Usenet logical network continues to be very important, even in the Internet era.

The Usenet Server Structure

In theory, all that is required of the Usenet structure is that each site be connected to at least one other site in some form. ...