Provided by: nntp_1.5.12.1-19_i386 bug

NAME

       nntpd - Network News Transfer Protocol server

SYNOPSIS

       /usr/lib/news/nntp/nntpd
       (with /usr/sbin/inetd, see below)

DESCRIPTION

       Nntpd  is  a  server that supports the proposed standard for the stream
       based transmission of network news articles.  It can be  used  both  by
       ‘‘reader/poster’’   clients   that   present  news  to  users,  and  by
       ‘‘transfer’’ clients that transport news between machines.   When  used
       with Internet TCP, nntpd operates at the port indicated in the ‘‘nntp’’
       service entry in /etc/services; the port number assigned by the Network
       Information Center for this service is 119.  For use with DECNET (which
       is only known to work under ULTRIX), define the NNTP object with NCP.

       ncp define object NNTP number 0 file /usr/lib/news/nntp/nntpd
       ncp define object NNTP default user guest type stream
       ncp set object NNTP all

       This manual page  describes  nntpd  from  version  1.5.9  of  the  NNTP
       package.

       Nntpd  can operate either as a stand-alone server, or as a server under
       inetd(8C).  For stand-alone  use,  nntpd  must  be  compiled  with  the
       -DALONE  option,  and  is  usually  invoked  at  system  startup by the
       /etc/rc.local script.  Under inetd(8C), the appropriate entry  must  be
       made  in  /etc/inetd.conf,  and the server must be compiled without the
       -DALONE flag. You may need to halt and restart  inetd(8C)  or  send  it
       SIGHUP to force it to reread /etc/inetd.conf.

       The  server handles clients on a one to one basis, forking to take care
       of clients as  they  request  connections.   Each  server  changes  its
       current  directory  to  the news spool directory ( /var/spool/news) and
       then executes commands from its client.  These commands  are  described
       in  ARPA Internet RFC 977, ‘‘Network News Transfer Protocol; A Proposed
       Standard for the Stream Based Transmission of News Articles.’’

CLIENT ACCESS

       Sites may choose to limit the hosts that can query the server for news.
       Further,  some  sites may not wish to allow certain hosts to post news.
       Finally, some sites may wish to restrict the  newsgroups  that  can  be
       accessed  from remote hosts.  Such limiting can be accomplished through
       an access file, /var/lib/news/nntp_access.  This file consists of three
       or four fields in the following form:

       host/net/*domain.suffix/address   read/xfer/both/no  post/no  newsgroups

       where  host is a valid host name as found in /etc/hosts, net is a valid
       network name as found in  /etc/networks,  *.domain.suffix  is  a  valid
       domain  part of a hostname preceeded by an asterisk, address is a valid
       internet address in the form of a dotted quad, and read,  xfer,
       both,  post, and no are the corresponding string constants.
       Newsgroups is an optional list  of  comma  separated  newsgroup  names.
       Anything  to  the right of a ‘#’ character is taken to be a comment and
       is ignored.

       The presence of an entry in this file implies that  specific  host,  or
       hosts on the named network, or hosts with a domain suffix that matches,
       are allowed to read news, but not to post news.  The absence of a entry
       corresponding  to a client’s host or network implies that the client is
       not allowed to read or post news.  Default permissions can  be  set  by
       having  the  first entry in the file be a host/net name of ‘‘default’’.
       If this is used, ‘‘default’’ must be the first entry.

       The first field to the right of the host/net entry specifies  the  read
       access of the host/net in question.  If the entry is ‘‘read,’’ matching
       hosts can read news. This means that all commands but  IHAVE  and  POST
       can be executed.  If the entry is ‘‘xfer,’’ however, matching hosts can
       only execute commands used for  transferring  news,  such  as  NEWNEWS,
       NEWGROUPS, IHAVE, and ARTICLE with message-id parameters.  If the entry
       is ‘‘both,’’ ths host can execute all commands but  POST.   The  string
       ‘‘no’’ denies read permission of any kind to a matching host.

       The  next  field  to the right defines whether a matching host has post
       permission:  if  the  field  is  ‘‘post’’  then  the  POST  command  is
       permitted;  if  the  field  is  ‘‘no,’’  then  matching clients are not
       allowed to post news.

       The next field is optional, and, if present, is a comma separated  list
       of newsgroup names that restrict the client’s reading ability.  Clients
       are not allowed  to  read  or  transfer  articles  in  newsgroup  names
       preceded  by  an exclamation point.  By default, clients are allowed to
       read all newsgroups.

       Nntpd is selective and searches for a  ‘‘best  match’’  when  searching
       this  file to check its client’s permissions.  That is, a specific host
       name match is used over a client being a member of a specified net.

EXAMPLE ACCESS FILE

       #
       # Example access file
       #
       default         xfer    no
       ucb-ether       read    post
       shadow          no      no
       *.stanford.edu  no      no
       ic              read    post     !ucb.postgres
       128.249.1.1     read    no

       The above file allows only  transfer  of  news  (i.e.,  no  reading  or
       posting)  by default.  Hosts on the network ‘‘ucb-ether’’ would be able
       to read and post news, however news transfer would not be allowed.  The
       host  ‘‘shadow’’ would not be allowed to read or post news.  Hosts that
       have a domain suffix of ‘‘.stanford.edu’’ are  denied  access  to  this
       server.   The  host ‘‘ic’’ is allowed to read and post news, but cannot
       access articles in the newsgroup ‘‘ucb.postgres’’ or any of  its  child
       newsgroups  (e.g.,  ‘‘ucb.postgres.core’’).  Finally, the host whose ip
       address is 128.249.1.1 is allowed to read but not  post.  If  you  have
       mutl-homed  host,  all  addresses  for that host will need to be listed
       with the same access information or things will not work as expected.

INFORMING USERS OF NEW NEWSGROUPS

       The NEWGROUPS command does  not  work  well  when  used  with  B  news.
       However,  C  news  provides  this  information and use of the NEWGROUPS
       command will be much more reliable.  For  those  sites  using  B  news,
       client programs can determine if newgroups have been created by testing
       for the difference in active file size from the previous session.

       Older versions of nntpd relied on  the  program  mkgrdates  to  prepare
       newsgroup  creation  information.   Mkgrdates  was  fallible  and could
       present a hefty load on the serving system.   Consequently,  it  is  no
       longer supported, and its use is discouraged.

AUTHORS

       Phil Lapsley (Internet: phil@berkeley.edu; UUCP: ...!ucbvax!phil)
       Stan Barber (Internet: sob@tmc.edu; UUCP: ...!bcm!sob)

SEE ALSO

       services(5), inetd(8C), rc.local(8)

       RFC  977, ‘‘Network News Transfer Protocol: A Proposed Standard for the
       Stream Based Transmission of News Articles.’’