Specifying Inbound Newsgroups
As of the end of March 1997, about 15,000 newsgroups existed (with more than
1.7GB of data in 200,000 messages), and the number is increasing at a rate of
more than 300 percent per year. This growth makes selecting which newsgroups to
download difficult. When you first configure a pull feed, you need to get the
active list of these groups into your news server so that you can pick the ones
you want to receive regularly. Fortunately, you don't need to type in this
active list. You can either get the active list as an ASCII file from your
USENET provider and import it using an import utility, or you can download the
information directly using NNTP. If you have a fast link such as a T1
connection, downloading the active list using NNTP takes only a few minutes. If
you have a dial-up 28.8Kbps connection, the download can take more than 20
minutes, and you might prefer to get the active list another way.
To start the process of downloading the active list with NNTP, select the
Inbound property page for the newsfeed. The first time you perform this process,
you will get the message, "There is no active list defined in this
newsfeed. Do you wish to import an active list?" If you answer no, you can
go back later and configure the newsfeed. If you answer yes, you can download
the list from the newsfeed provider using NNTP or import a file containing the
active list. In most cases, you can simply choose to use the NNTP method.
At this point, you see a dialog box and progress indicator that show the
progress of the active list download from the provider. If your Internet
connection is down or if you have incorrectly entered the provider's name and
requisite security information in the connection page for the newsfeed, you will
get an error message within a few seconds. However, if you establish a
connection, you can gauge the progress of the download from the sliding
indicator. Keep in mind that some ISPs have different USENET servers for news
server or news client access--make sure you don't choose the wrong one. On two
occasions, I've seen the progress indicator climb to about 60 percent and freeze
when trying to pull a newsfeed from a news server designated for client access.
Unfortunately, you don't see any error message, and the newsgroups appear to be
downloading based on your ability to access the server using Telnet or a desktop
news client.
After you download the active list, Exchange stores it locally. Every time
you subsequently open the Inbound property page for the newsfeed, you see a
brief message saying, "Setting up the Active File... Initializing."
This message indicates that Exchange is reading the local copy of the active
list. After you complete this step, you can see a list of the newsgroups
available on the provider's server. Screen 8
shows some of the newsgroups available on msnews.microsoft.com as of March.
The list in Screen 8
does not imply that these newsgroups contain any messages or that any authority has
evaluated any of the messages therein. To select a newsgroup to download, highlight
the group and click Include. When you
select a newsgroup, you are also selecting all subgroups of the newsgroup, regardless
of whether you want to replicate these subgroups to your server.
After you select a group, the folder in the list changes appearance from a blank
folder to a small newspaper. In Screen 8, you can see
that I am not downloading the cinemania group, but I am downloading the catapult folder and all its
subgroups. When you click OK to close this property page, the Exchange server
contacts the news server for the newsfeed (here msnews.microsoft.com) on the
prearranged schedule and requests any new items in the included newsgroups. Your
Exchange server will then download all items added to the newsgroups at
Microsoft since the last time your server polled msnews.microsoft.com and upload
to Microsoft any items your local Exchange users posted to the corresponding
public folders.
Client Access
Now that you have configured a pull newsfeed, you can access the newsgroups
with either a Messaging API (MAPI) or an NNTP client (for details about NNTP
client access, see my article, "Spread the News with Internet News Server,"
June 1997). If you open an Outlook client, you will see the newsgroups you have
pulled down in the Internet Newsgroups folder, similar to what you see in
Screen 9.
In this case, I am browsing the microsoft.public.frontpage.client
newsgroup, and I've just read a message entitled "virtural server wont
start" posted by some unfortunate soul. If you use an NNTP client such as
the Microsoft Internet News client configured to use the Exchange server as its
USENET server, you will see the same hierarchy and message.
Screen 10 shows the
Microsoft Internet News client displaying the microsoft.public.frontpage.client newsgroup.
If you select Enable Client Access on the NNTP General property page (see
Screen 2), you can view and respond to the same Exchange public
folders with either NNTP or MAPI clients. Exchange will replicate responses
you post to Microsoft during the next scheduled connection and replicate your
responses to other news servers with feeds from msnews.microsoft.com.
As you can see, setting up a news server and a pull feed is astonishingly
simple. However, keep in mind one caveat: Most newsgroups on the Internet are
not moderated; that is, nobody is monitoring the messages being posted, and
therefore nobody is responsible for controlling the content of the newsgroups.
This freedom to post whatever you want whenever you want is both useful and
dangerous and can lead to major arguments within companies as to which
newsgroups to carry. For example, take the newsgroup alt.2600 and its subgroups
available on the public USENET servers. In this newsgroup, you will find a lot
of people posting ways to defeat servers, source code for viruses, ways to
bypass known commercial firewalls, and all sorts of unsavory and exciting stuff.
By reading this newsgroup, you can learn about potential threats to your own
network and your customers' networks. Study this newsgroup, and you can become a
security expert who is adept at fending off attacks by hackers. This ability to
access such information is good. However, letting that information and code
loose on your own network is potentially disastrous. You have to make a choice
between providing valuable but dangerous information to your users, or censoring
it and ensuring that your company's engineers read only publications approved by
software publishers' legal departments.