Linux Network Administrator Guide, Second Edition

qualified domain name of your mail host after the fromhost statement.

The pathhost line defines the hostname INN is to add to the Path: header field whenever it receives an article. In most cases, you will want to use the fully qualified domain name of your news server; you can then omit this field since that is the default. Occasionally you may want to use a generic name, such as news.vbrew.com, when serving a large domain. Doing this allows you to move the news system easily to a different host, should you choose to at some time.

The next line contains the organization keyword. This statement allows you to configure what text inews will put into the Organization: line of articles posted by your local users. Formally, you would place a description of your organization or your organization's name in full here. Should you not wish to be so formal, it is fashionable for organizations with a sense of humor to exhibit it here.

The organization keyword is mandatory and specifies the pathname of the mail transport agent that will be used for posting moderator messages. %s is replaced by the moderator email address.

The moderatormailer entry defines a default address used when a user tries to post to a moderated newsgroup. The list of moderator addresses for each newsgroup is usually kept in a separate file, but you will have a hard time keeping track of all of them. The moderatormailer entry is therefore consulted as a last resort; if it is defined, inews will replace the %s string with the (slightly transformed) newsgroup name and send the entire article to this address. For instance, when posting to soc.feminism, the article is mailed to [email protected], given the above configuration. At UUNET, there should be a mail alias installed for each of these submissions addresses that automatically forwards all messages to the appropriate moderator.

Finally, each of the remaining entries specifies the location of some component file or executable belonging to INN. If you've installed INN from a package, these paths should have been configured for you. If you're installing from source, you'll need to ensure that they reflect where you've installed INN.

Configuring Newsgroups

The news administrator on a system is able to control which newsgroups users have access to. INN provides two configuration files that allow the administrator to decide which newsgroups to support and provide descriptions for them.

The active and newsgroups files

The active and newsgroups files are used to store and describe the newsgroups hosted by this news server. They list which newsgroups we are interested in receiving and serving articles for, and administrative information about them. These files are found in the /var/lib/news/ directory.

The active file determines which newsgroups this server supports. Its syntax is straightforward. Each line in the active file has four fields delimited by whitespace:

name himark lomark flags

The name field is the name of the newsgroup. The himark field is the highest number that has been used for an article in that newsgroup. The lomark field is the lowest active number in use in the newsgroup. To illustrate how this works, consider the follow scenario. Imagine that we have a newly created newsgroup: himark and lowmark are both 0 because there are no articles. If we post 5 articles, they will be numbered 1 through 5. himark will now equal 5, the highest numbered article, and lowmark will equal 1, the lowest active article. If article 5 is cancelled there will be no change; himark will remain at 5 to ensure that that article number is not reallocated and lowmark will remain at 1, the lowest active article. If we now cancel article 1, himark will remain unchanged, but lowmark will now equal 2, because 1 is no longer active. If we now post a new article, it will be assigned article number 6, so himark will now equal 6. Article 5 has been in use, so we won't reassign it. lowmark remains at 2. This mechanism allows us to easily allocate unique article numbers for new articles and to calculate approximately how many active articles there are in the group: himark-lowmark.

The field may contain one of the following:

y

Posting directly to this news server is allowed.

n

Posting directly to this news server is not allowed. This prevents newsreaders from posting directly to this news server. New articles may only be received from other news servers.

m

The group is moderated. Any articles posted to this newsgroup are forwarded to the newsgroup moderator for approval before they enter the newsgroup. Most newsgroups are unmoderated.

j

Articles in this group are not kept, but only passed on. This causes the news server to accept the article, but all it will do with it is pass it to the 'up-stream' news servers. It will not make the articles available to newsreaders reading from this server.

x

Articles cannot be posted to this newsgroup. The only way that news articles are delivered to this server is by feeding them from another news server. Newsreaders may not directly write articles to this server.

=foo.bar

Articles are locally filed into the ``foo.bar'' group.

In our simple server configuration we'll carry a small number of newsgroups, so our /var/lib/news/active file will look like:

control 0000000000 0000000001 y
junk 0000000000 0000000001 y
rec.crafts.brewing 0000000000 0000000001 y
rec.crafts.brewing.ales 0000000000 0000000001 y
rec.crafts.brewing.badtaste 0000000000 0000000001 y
rec.crafts.brewing.brandy 0000000000 0000000001 y
rec.crafts.brewing.champagne 0000000000 0000000001 y
rec.crafts.brewing.private 0000000000 0000000001 y

The himark and lomark numbers in this example are those you would use when creating new newsgroups. The himark and lomark numbers will look quite different for a newsgroup that has been active for some time.

The newsgroups file is even simpler. It provides one-line descriptions of newsgroups. Some newsreaders are able to read and present this information to a user to help them decide whether they want to subscribe.

The format of the newsgroups file is simply:

name description

The name field is the name of a newsgroup, and the