Network News Transfer Protocol (NNTP)


As with the other Internet protocols, IIS provides support for the Network News Transport Protocol (NNTP) . Since the NNTP virtual server is installed and enabled by default when you install Exchange Server 2003, any NNTP-based newsreader application can be used to connect to and use public folders right away. Like the other protocols, the NNTP virtual server is configured using a number of property pages. Table 7.8 provides an overview of the property pages for this object.

Table 7.8: NNTP Property Pages

Property Page

Description

General

This page is used to assign an IP address to the virtual server. The default is for the server to have access to all IP interfaces configured on the server. You can select a specific IP address or use the Advanced button to configure IP address and TCP port information. This page is used to configure how long an idle NNTP connection will be held open before automatically closing and to limit the number of connections that the virtual server will allow. In addition, this page can be used to configure a path header, which is used by other Usenet servers to prevent a situation called ‚“looping, ‚½ which can happen when a Usenet server is connected to multiple providers. Finally, this page can be used to enable logging for the NNTP service for troubleshooting purposes.

Access

An Exchange server can allow NNTP clients to be authenticated with the same protocols that were options with POP3. But while the options are the same for both NNTP and POP3, each can be configured with a different set of authentication protocols.

Settings

The Settings page provides a number of options for configuring the NNTP protocol:

The Allow Client Posting option controls whether users with NNTPbased newsreaders can post messages using the NNTP protocol. If this option is enabled, you can also control how large of a message, in kilobytes, can be posted and how much data, in megabytes, can be posted during a single user session.

The Allow Feed Posting option works the same way as the Allow Client Posting option, but it controls whether or not messages can be automatically posted by newsfeeds, which are discussed later in the chapter.

The Allow Server To Pull News Articles From This Server option controls whether other Usenet servers can use the NNTP protocol to pull messages in a public folder to their own server.

The Control Messages option is used to allow Usenet servers to govern the traffic between servers.

The final three options control the domain and address of moderators for moderated newsgroups. In a moderated newsgroup, a designated moderator must approve messages before they are posted to a folder.

Creating Newsgroups

When NNTP is installed, two virtual directories are created by default:

  • The default directory creates new newsgroups and stores them in the Newsgroups public folder.

  • The control directory contains three folders for the three primary control commands, as seen in Figure 7.23: Remove Articles, Create Newsgroup, and Remove Newsgroup.


    Figure 7.23: Viewing newsgroups in System Manager

You can create new newsgroups using either a MAPI client or System Manager. The procedure for creating a newsgroup within a MAPI client varies, but it usually follows a pretty simple procedure of selecting a parent folder and creating a new folder inside of it. In System Manager, you can create a new newsgroup by expanding an NNTP virtual server, right-clicking the Newsgroups container inside it, and selecting the New Newsgroup command from the shortcut menu.

In addition to creating your own newsgroups, you can also configure Exchange to pull newsgroups and their contents from a Usenet server on the Internet. Before you learn to do that, however, a brief overview of Usenet itself is in order.

A Usenet Overview

Usenet is a network within the Internet that is composed of numerous servers containing information on a variety of topics. Each organized topic is called a newsgroup, which can be thought of as a discussion group or a bulletin board. The Usenet servers are also referred to as newsgroup servers. Users access these newsgroups to post information or to read other people ‚ s postings. Users interact with newsgroups through client applications referred to as newsgroup readers.

Clients and servers use the Network News Transfer Protocol (NNTP) to transfer information across Usenet. When a client reads or posts information to a newsgroup server, NNTP is used for this exchange.

NNTP is also used to transfer newsgroup content between servers. This function is referred to as a newsfeed . A newsgroup server can be configured to send all or some of its newsgroups to other servers. When one server actively sends information to another server, it is referred to as a push feed (it is also referred to as publishing). A server also can be configured to request that information be sent to it from another server. This is referred to as a pull feed . Push feeds are usually used with large newsfeeds. A pull feed allows a local administrator to specify which and when newsgroups are received.

Exchange Server 2003 can function as a full Usenet server and exchange newsgroup information with other Usenet servers on the Internet. This is done through the Newsfeed Configuration Wizard. The wizard prompts the installer for such information as the name of the Usenet host; the host ‚ s IP address; and the type of newsfeed, such as inbound (i.e., receiving data), outbound (i.e., publishing data), or inbound and outbound. Newsfeeds basically enable an Exchange server to function as a newsgroup server. It can publish public folder content as newsfeeds to other Usenet servers. It also can receive newsfeeds from the Usenet and place newsgroups in public folders. To receive newsfeeds, it can either pull a newsfeed or receive a push. See Figure 7.24 for an illustration of this process.


Figure 7.24: Newsfeeds and the Usenet

Once a newsfeed is configured, it is represented in the Feeds container of an NNTP virtual server as an object. The property pages of a Newsfeed object can be used to configure the newsfeed after its creation. Much of the information that was entered in the wizard can be later viewed and modified through the Newsfeed object. For example, if the IP address of the Usenet host changes, the new address can be entered in the properties of that newsfeed rather than creating a new newsfeed with the wizard.




MCSA[s]MCSE
MCSA[s]MCSE
ISBN: 735621527
EAN: N/A
Year: 2004
Pages: 160

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