To help provide a better understanding of this Internet capability, this chapter goes over the history of newsgroups before moving into the actual configuration of the NNTP and INS functions in Exchange.
Tom Truscott and James Ellis invented a system to pass information between UNIX systems. This system, called UNIX-to-UNIX CoPy or UUCP, was used to pass files from a server at Duke to a server at the University of North Carolina and the reverse. As the technology matured, the software was rewritten to handle a larger volume of data. The original version was limited in the number of articles per newsgroup each day it could manage. Today, the system is called UseNet and is estimated at over 250,000 sites worldwide hosting over 18,000 newsgroups. However, UseNet had its share of problems. Luckily, several systems and solutions were created to address these problems.
First, there was a need to develop an efficient way to distribute the news to non-UNIX clients. Many people began to realize there was valuable information in the newsgroups, and they wanted to access them from non-UNIX desktops. Other users needed a newsreader that would help format the screen and take care of SMTP-like transmissions for the newsfeed. Still other users found the current versions of the newsreader software too cryptic to use. Also, this system needed more intelligence. It needed a built-in method that knew what to send and when to send it, the ability to record the condition of the server's last transmission, and everything necessary to run on top of a streaming protocol like TCP/IP. In February of 1986, an RFC appeared that established a higher-level internetwork protocol that would fulfill the needed requirements. It was called NNTP, and it became the natural choice for sites using the Internet to transfer data in the form of articles. NNTP has also been chosen by Microsoft to run its Exchange 5.5 Internet News Service.
NOTE: An Exchange Server site is not the same as a UseNet site. A UseNet site is either a Backbone Server or an Intermediate server organized into an internetwork to pass data from one site to the next.
The basic building block of UseNet is a newsgroup. As mentioned earlier, newsgroups are an online discussion group that are a many-to-many communication whereas e-mail is one-to-one.
These newsgroups are organized by subject into directories and subdirectories on the Backbone Sites (a key UseNet site that processes a large amount of UseNet traffic). These newsgroups (directories) are categorized by subject, area, and place. Examples of this follow.
Examples of Subject:
Examples of Area:
Examples of Place:
Each category of the newsgroup has one or more subcategories. A fictitious example may be the category cartoons, which may be called cart. The cartoon area could have several categories under it. One category may be loon (short for Looneytunes). Under the loon category, there may be a subject called Rat. The newsgroup name would be cart.loon.Rat. It could be broken down even further specifically into different interests. At the leaf node, people can send messages and start strings of conversations about their favorite topics by using newsreader software. A leaf node is a UseNet site that originates and reads UseNet news. It does not relay any UseNet traffic like a backbone site. The newsreader software will aid in pulling these articles from the leaf node machine. It is important to note that you could send and read the newsgroup articles from Backbone and Intermediate sites, but this may not be practical considering the design of these sites.
When you post an article, it is spooled into a specific area where it is stored until another server contacts this server and queries for newsgroups. Then it is passed to the requesting server. This happens with all servers sharing newsgroups until all machines on UseNet are updated. This is automatically done many, many times a day at predetermined times. Finally, the last server that receives information sends a message back to the parent server that it will not pass news. There are three categories of servers that participate in this flow:
See Figure 23.1 for more information.
FIG. 23.1 The flow of Information within UseNet.
The flow from one UseNet site to another is called newsfeed. Each UseNet site receiving a newsfeed can be configured to accept and generate an NNTP connection and newsfeed to an outside source like Exchange Server running the INS. The INS processes this flow of information and converts it into a usable Exchange format to be accessed by a compatible Exchange client. To participate in the UseNet, you will connect your Exchange server to an Internet Service Provider (ISP) or Internet host machine offering newsfeeds and NNTP connection.
Keep in mind that once you configure Exchange to participate in UseNet newsfeeds by allowing inbound and outbound posting, you are effectively including your Exchange Server site in the UseNet loop. It is important to understand Internet firewall issues as well as the type of newsgroups that newsfeeds are being established to access. Also, multiple newsfeeds can be established from different providers, so be careful not to overlap or duplicate the information (two feeds from different sources streaming in the same information) supplied by the newsfeed to your Exchange server.
Two types of newsfeeds can be used in Exchange, push and pull. The basic difference is who initiates the newsfeed. With a push feed, your provider initiates the newsfeed and essentially controls which newgroups you receive. Obviously, you will want to tell your provider which newsgroups your company needs, but from a configuration standpoint, the provider is in the driver's seat. The advantage of the push feed is the capability of better handling of large newsfeeds.
The pull feed works well for smaller newsfeeds and for UseNet sources that are not compatible with an Exchange push feed. Here, you configure the connection and choose which newsgroups your company needs. Then, Exchange initiates the newsfeed and retrieves any new messages. This feed allows more control of the flow of information to and from your Exchange server.
Two more terms need to be defined before a discussion of inbound and outbound newsfeeds. Typically, a UseNet provider will have two hosts in one of two roles: an inbound host and an outbound host. These names can be somewhat confusing because the flow of information is the reverse compared to the host type. An inbound host is the host that provides a newsfeed into Exchange. An outbound host is the host that accepts a newsfeed from your Exchange server. The inbound and outbound host roles can be on the same machine, but for the purposes of example, this discussion places the roles on separate machines.
So to put everything together, you can use a pull feed to pull messages from your provider's inbound host. Using a push feed, the inbound host initiates the connection and pushes the newsfeed messages to your Exchange server. Both of these transfers are called inbound newsfeeds.
Alternatively, you can use a push feed to send or push messages from Exchange to your provider's outbound host. You can also use a pull feed where the outbound host will receive messages from Exchange. Both of these transfers are called outbound newsfeeds.
The NNTP protocol works with either push or pull feeds to get or receive a newsgroup. The communication between servers is governed by a set of rules built into the NNTP protocol. So, while the push and pull feeds are dynamically working, the NNTP protocol is communicating on a different level of the internetwork protocol stack in achieving control of the desired amount of the message flow, coming in or out of the servers.
When planning the roll-out of INS in your organization, you must consider the large amount of resources that newsgroups can require. Unless you are installing a dedicated Exchange News Server or resources (such as server processing and storage and Internet connection bandwidth) are not an issue, it is recommended to first establish an INS newsfeed to a few limited newsgroups. When resources are limited, it is critical to understand the effects newsfeeds can have on overall network and Exchange Server performance. There are many options in Exchange when configuring INS that allow complete control of how resources are utilized.
Having answers for the following questions will make the initial installation and configuration of NNTP much easier.
What is your Fully Qualified Domain Name or Internet Protocol (IP) address of the Microsoft Exchange Server computer that is running the Internet News Service? Do you plan to use a pull or push newsfeed for inbound messages or outbound messages?
How are you connecting to your provider? Will you use a dial-up (through DUN) or direct LAN connection to communicate with the host computer?
For a push newsfeed, do you want a secured inbound newsfeed? You will need to supply your ISP providing the newsfeed service with an inbound host account and password.
Which newsgroups will be downloaded by INS to the Exchange Public Folders, who has permission to access them, how long are inbound postings retained, and do you allow outbound posting? Have a plan on the organization of newsgroups on your Exchange server.
The following are questions that you will need to ask the ISP provider with the subscribed UseNet host that you are establishing a newsfeed with:
Specifically, ask your UseNet or Internet site administrator for your FQDN (Fully Qualified Domain Name).
How will you receive your active file? There are several ways to obtain this file from your provider. It can be e-mailed or sent by FTP (File Transfer Protocol) to you or downloaded directly from the host through the INS connection.
Who is responsible for the list of newsgroups you need to subscribe to? If you are planning to use push feeds, a list of newsgroups that you need to subscribe to must be sent to your newsfeed provider.
To install an NNTP connection to another Microsoft Exchange server or foreign system, there are five primary steps to follow:
The information provided in the following sections will allow you to achieve these goals.
When the appropriate software and hardware is installed (including Inter/intranet connectivity) on the Windows NT/Exchange server that will be handling the NNTP connection, you are ready to proceed with running the Newsfeed Configuration Wizard. The Newsfeed Configuration Wizard makes installing the INS easy. All you must do is supply the answers to several questions that were covered earlier in this section. Here are some of the items the wizard will ask you for:
The Configuration procedure for the NNTP connection runs through a series of setup wizard screens that will guide you.
To run the Newsfeed Configuration Wizard, from the Exchange Administrator program, select the File menu, then New Other, and then Newsfeed. The NNTP Configuration Wizard appears (see Figure 23.2).
The first screen reminds you to contact your NNTP newsfeed service provider for the information needed in configuring NNTP.
NOTE: If you are using Dial-Up Networking, the Dial-Up Network has to have an entry for the NNTP remote site's phone number to answer the wizard's question on who is your UseNet provider.
With the information you have collected, you are ready to proceed with the NNTP installation by choosing Next on the first wizard screen.
FIG. 23.2 The Newsfeed Configuration Wizard will take you through NNTP connector setup.
The next wizard screen requires you to fill in the UseNet site name with a Fully Qualified Domain Name (FQDN). The Server To Install On is automatically selected. You can choose to install this connector on any server in the organization providing that there are proper permissions and administrative rights. Choose the Next button on the bottom of the screen.
It is important to remember that you are configuring a newsfeed that will transfer through a connection that has been configured with NNTP. Note that NNTP is a component that moves data (news) across an internetwork, between sites, and into Exchange public folders. Then a client is used to read and post news messages as well as to post replies into the public folders. Those messages eventually are posted to the appropriate newsgroup (see Figure 23.3).
FIG. 23.3 You need to have FQDN for your Newsfeed server.
It is necessary to configure whether you are going to pull or push with a newsfeed from the UseNet provider. A pull newsfeed is associated with inbound newsfeed or an upstream newsfeed. An inbound pull newsfeed refers to the Exchange server initiating the call to the newsfeed provider.
NNTP controls the conversation, which ends when the sender hangs up. The news articles that NNTP distributes on the Exchange server will be handled in public folders.
Push feeds are associated with inbound and outbound newsfeeds. When a push inbound connection is established, the host initiates the call to the Exchange server. Then the Exchange server is configured to accept the inbound push newsfeed. The newsfeed is filtered through an active file. Further, you must establish a push outbound newsfeed at your newsfeed provider and establish the security issues that go with the outbound feed.
The NNTP Configuration Wizard provides three choices of newsfeeds:
The NNTP Configuration Wizard also provides the choice of the type of inbound newsfeed:
FIG. 23.4 Deciding what type of newsfeed to create.
The Newsfeed Configuration Wizard begins to check on your network protocol. The network is either a LAN or Dial-Up Networking (DUN). The network should be configured before using the wizard. The phone book should have an entry for the Newsfeed Service provider. If there are no DUN phone book entries, the wizard will flash a warning message informing the user that there are no phone book entries. After clearing the warning message, you are returned to the wizard and the connection using DUN option will be grayed out. If there is a phone book entry, it will appear in the box and you can select the appropriate site. If there is further authentication needed for your UseNet host, there are entries for Account and Password (see Figure 23.5).
FIG. 23.5 Deciding on the network type. If necessary, enter UseNet Host Account and Password.
On this screen the wizard program sets up a connection schedule, which specifies how often the Microsoft Exchange Server computer will connect to your newsfeed provider. The drop-down menu has intervals of 15 minutes, 1 hour, 3 hours, 6 hours, 12 hours, and 24 hours. From the Exchange Wizard program, choose Next (see Figure 23.6).
FIG. 23.6 Setting up the time intervals for the newsfeed connection.
The UseNet site name is entered in this box (see Figure 23.7).
FIG. 23.7 Entering your site name for your newsfeed provider.
The wizard provides space to enter the host's name or IP address. There is also a box in which a host name or IP address may be added for additional host computers (see Figure 23.8).
FIG. 23.8 An IP address or host name of the inbound host computer.
The next screen in the wizard allows the options for a secure connection to the provider. Ask the newsfeed provider if a Login and password are required. With Exchange 5.5 NNTP, there is now Secure Socket Layer (SSL) support. If your host provider supports SSL, you can select this. If your provider does not require any of this security, you can skip it. By choosing the Next button, you will be ready to install your NNTP Internet News Service (see Figure 23.9).
You will need to provide the Exchange Service account password to install the INS for the first time (see Figure 23.10).
FIG. 23.9 Security for your Internet provider if it is required.
FIG. 23.10 Providing an Exchange Service account password.
At this point, the Internet Newsfeed Service is installed and started. However, no newsgroups have been selected for the newsfeed. The wizard indicates that there still must be a newsgroup selected. One reason that the wizard hasn't asked for a newsgroup up to this point is that it needs the road map to all News Groups, which is called the Active File. However, the Newsfeed needs to connect to the host so that it can download this file (see Figure 23.11).
The administrator will delete and create all the Internet Newsgroup public folders and receive INS alert notifications. Choose a person with administrator rights in Exchange for these tasks (see Figure 23.12).
FIG. 23.11 The wizard needs to connect before downloading the active file.
FIG. 23.12 You should choose a Newsgroup administrator with Exchange administrator rights.
Exchange Server has made the connection with the host computer through NNTP. The wizard wants to download the active file, which is a road map to Newsgroups or conversations throughout the world. The wizard gives three options:
FIG. 23.13 For inbound connections the Active file is a road map to the world's newsgroups.
After the Active File is loaded and you have proceeded to the next screen,. you can select the newsgroups that you want to subscribe to. If you expand the root directory of the news server shown in the box, the various newsgroups will be displayed. To subscribe to a specific newsgroup, highlight it and click Include. Once you have selected all the newsgroups you want, click the Next button and all the Exchange public folders will be created for those subscribed newsgroups (see Figure 23.14).
FIG. 23.14 Selecting the newsgroups you want to subscribe to.
The wizard is completed. The INS is running and by default has enabled the newsfeed you just installed. However, if you have installed a push newsfeed, it is now time to call your provider to coordinate the newsgroups you have subscribed to and have them activate the push from their host server. Clicking the Finish button completes the installation process (see Figure 23.15).
FIG. 23.15 The wizard has completed installing the Microsoft Internet News Service.
The NNTP Connector property pages allow you to make configuration changes to any installed NNTP newsfeed. Each NNTP Newsfeed property page is covered in the following sections.
The General Page Use the NNTP General page to change the basic communication options for a selected newsfeed. The following steps guide you through configuring the NNTP Newsfeed General page:
The Messages Page Use the Messages Properties page to specify the maximum incoming and outgoing and message size in your newsfeed. Complete the following steps:
No limit | There isn't a size limit for the message. |
Maximum(K) | Select and type a number representing the largest size of message that can be sent. |
FIG. 23.16 The General tab.
FIG. 23.17 Entering the size limit of incoming and outgoing messages.
The Hosts Page Set Site and Host name or IP address for establishing a connection to the remote newsfeed Hosts server. Additional inbound hosts are set here:
FIG. 23.18 Entering the remote site and host name.
The Connection Page Set the connection type, LAN or dial-up connections to your hosts, by completing the following steps:
Refresh List | Updates current connections. |
New Connections | To add a new dial-up connection to the list of connections, you must Refresh to update list. |
Connection | Select from the list of available Dial-Up Networking connections. |
Account | Account name of dial-up connections. |
Password | The password for the dial-up connection if necessary. Confirm password. Verify that the password is correct. |
The Security Page The Security page applies to both inbound and outbound feeds. Unless required for connection to the host computer, this page is optional (see Figure 23.20).
An inbound feed is a push to the newsfeed server. An outbound feed is a pull to the newsfeed server or the reverse. Security is set up in consideration of newsfeed server calling an Exchange server or Exchange server calling your newsfeed provider. Complete the following steps:
FIG. 23.19 You can select either Local Area Network or Dial-Up Networking.
The Schedule Page Use the Schedule properties page to control how often the NNTP newsfeed initiates a connection to the host server to update the newsgroups that you subscribed to. Scheduling specific times for newsfeed sending and receiving newsgroup updates can be an excellent way to limit the effects on network and server resources during peak production hours. Complete the following steps:
Never | In effect, disables newsfeed. |
Always | Starts connections every five minutes. |
Selected Times | Assigns specific connections times in the Schedule grid. |
FIG. 23.20 Entering optional security data for inbound or out- bound feed.
1 Hour | Displays the schedule grid in one-hour increments. |
15 Min. | Displays the schedule grid in 15-minute increments. |
FIG. 23.21 Scheduling connection times for newsgroup updates.
The Inbound Page Inbound newsfeeds are typically a push feed from your UseNet host. The inbound newsfeed can also be installed as a pull feed. The type of inbound newsfeed is selected during initial newsfeed installation with the configuration wizard. Consequently, you cannot change the type of inbound feed once the newsfeed is installed. To change the type of inbound newsfeed, you must delete the newsfeed and rerun the wizard. You can select which news- groups you want to subscribe to on this property page. The list of available newsgroup servers reflects the active file that was downloaded during the configuration wizard process. Configure as follows:
For pull-type newsfeeds:
For push-type newsfeeds:
FIG. 23.22 A push inbound newsfeed.
The Outbound Page The Outbound Newsfeed is responsible for sending or posting messages on a newsgroup. If the News host computer needs to pull messages from your Exchange server, you need only configure NNTP client support on your computer. The host computer can then pull messages off your Exchange server acting as though it was an NNTP newsreader. Configure your outbound newsfeed (see Figure 23.24) as follows:
FIG. 23.23 A pull inbound newsfeed.
FIG. 23.24 Configuring outbound newsfeed.
The Advanced Page Use the Mark All Newsgroup Messages As Already Delivered option to mark all queued messages as delivered. This flushes the queue of messages waiting to be processed, allowing the Exchange server or another host computer to catch up to the most recent newsgroup postings (see Figure 23.25).
FIG. 23.25 Flushing the newsgroup queue of all messages.
Newsgroup hierarchies are folders built with UseNet public folders from newsfeed. Selecting a parent folder from an existing public folder enables you to rearrange this folder by user preference. Exchange 5.5 enables the organization to build their own order of folders from their newsfeed (see Figure 23.26).
Complete the following steps to add and remove public folders to a newsgroup hierarchy:
This section covers the Network News Transfer Protocol (NNTP). You can adjust a few settings from the NNTP protocol property page. These property settings can be configured to affect the Protocols NNTP object at both the site and server level. Default settings are set at the site level; you can use site defaults or change the settings at the server level for a specific server. Here's an overview of some key pages (see Figures 23.27 and 23.28):
FIG. 23.26 You can add or remove public folders to create newsgroup hierarchies.
FIG. 23.27 Setting the Exchange site-level defaults.
Use the General page to set the defaults for your site or server NNTP object. Complete the following steps:
FIG. 23.28 Setting the Exchange server-level settings.
Note that the Directory is not adjustable and is named during installation.
Use the Permissions property page (see Figure 23.29) to specify the rights that users or groups have on this protocol. Permissions can be used to delegate roles. Roles are sets of rights that define what type of access a user has.
The Newsfeed page allows you to view the properties of newsfeeds that have been configured by the Newsfeed Wizard. Clicking the Properties button will show you the properties for the highlighted newsfeed. The Properties button is a fast and easy way to reference your newsfeed configurations. At the server level, there is a Create Active File option button to allow you to update the server active file (see Figure 23.30).
Authentication occurs when a client logs on to the server and password and account information are compared and authenticated. The authentication process provides a user with certain permissions that provide access to resources. The problem with authentication is that people can intercept the password and account. After they have access to your accounts, they have access to your computer. With Exchange Server, six options are available for authentication: Basic Clear-Text, Windows NT Challenge/Response, MCIS Membership System, and then each of those choices using SSL Encryption.
FIG. 23.29 The Permissions tab.
FIG. 23.30 You can highlight the newsfeed and choose Properties.
Use the following steps to configure Authentication:
FIG. 23.31 Choosing the authentication you need.
The Message Format properties cover formats like MIME, uuencode, and Multipart forms. Messages come into Exchange in foreign formats that need to be converted at the NNTP site or server object level. This applies to both incoming and outgoing messages. Exchange Server messages are converted when an NNTP client retrieves them. Messages that are sent by an Internet user are not converted, and NNTP clients retrieve messages in the format that they were originally sent. The Message Format Properties pages can be set to convert these message formats. There are also ways to control the message queue. Topics to be covered are
NNTP Messages coming from the Internet are often retrieved by NNTP clients and are unreadable. This applies to NNTP messages arriving and leaving. On the NNTP object protocol, you can set encoding methods to convert the newsfeed into a readable format:
Microsoft Exchange Server has a way it can control messages. Exchange can queue messages until you decide to use the messages. This can be helpful in many different ways. One possible use is that NNTP host computers use a control message to communicate with one another. Control messages are used to create and delete newsgroups and cancel messages that have already been posted through an inbound newsfeed. When Microsoft Exchange Server receives a control message to delete or add a newsgroup, it queues the control messages until you decide to reject or accept these new newsgroups. Exchange can control these messages through the Control Message page (see Figure 23.33):
FIG. 23.32 The Select Message Format page.
FIG. 23.33 You can delete or accept control messages.
A user can be given permissions to an NNTP object. You can give permissions for anonymous access so a user doesn't have to provide a unique login ID. The permissions limit the access that this type of user has on that object. Complete the following steps:
FIG. 23.34 The Anonymous tab.
This is the setting for how your Exchange server handles NNTP intervals of inactivity (see Figure 23.35).
FIG. 23.35 Idle time-out is set to control how your server handles intervals of inactivity.
Diagnostics logging levels determine which Exchange Server events are written to the Windows NT application event log. You can set logging levels to provide information in varying levels of detail (see Figure 23.36). Events can range from significant events (application failures), to moderately important events (receipt message across gateway), to events relevant only to debugging. Usually you log only critical events. When you are not troubleshooting NNTP, it is recommended that you turn off logging because large log files can be generated rapidly depending on log level and NNTP activity.
FIG. 23.36 You can use diagnostics logging for NNTP troubleshooting.
No client/server discussion would be complete without touching on the client. You can configure the client through the user mailbox or Custom Recipient Address. Authentication must be enabled at the server, the mailbox, or a custom recipient. The client cannot connect if NNTP has been disabled. Set NNTP client options from a mailbox or custom recipient properties (see Figure 23.37).
FIG. 23.37 Enabling NNTP for a recipient.
FIG. 23.38 Setting NNTP and messaging format options at the user level.
Internet News options can be configured on the Internet Newsgroup public folders properties page when accessed from an Outlook client (see Figures 23.39 and 23.40).
FIG. 23.39 Configuring properties for Internet Newsgroup Public Folders.
NNTP options can be set for individual subfolders in the Internet Newsgroup public folder on the specific folder's properties page when accessed in the Exchange Administration program (see Figure 23.41).
FIG. 23.40 Public folders for users with newsreader software.