ZEPHYRD(8)						      System Manager's Manual							ZEPHYRD(8)

NAME

       zephyrd - Zephyr server daemon

SYNOPSIS

       /usr/etc/zephyrd [ -d ]

DESCRIPTION

       zephyrd is the central server for the Zephyr Notification System.  It maintains a location database of all currently logged-in users, and a
       subscription database for each user's Zephyr clients.

       zephyrd communicates with daemons running on other Zephyr server hosts, to provide a reliable service.

       While running, any unusual conditions are recorded via syslog(3) to facility local6 at various levels.  The -d option  enables  logging	of
       additional debugging information.

       When  a zephyrd is executed, it requests a list of server machines from Hesiod and initializes its state from any zephyrds executing on the
       other known servers.  This initialization is only performed after the zephyrds have authenticated themselves to each  other  via  Kerberos.
       The server then enters a dispatch loop, servicing requests from clients and other servers.

SIGNALS

       SIGUSR1 enables logging of additional debugging information.
       SIGUSR2 disables the logging of additional debugging information.
       SIGHUP  causes zephyrd to re-read the default subscription file and to re-query Hesiod about valid peers.  Any peers which are not respond-
       ing and no longer mentioned in Hesiod are flushed; any peers not previously named by Hesiod are added.
       SIGINT and SIGTERM cause zephyrd to gracefully shut down.
       SIGFPE causes zephyrd to dump the location and subscription databases to /var/tmp/zephyr.db in an ASCII format.

ACCESS CONTROL

       Certain notice classes are restricted by the Zephyr server.  Each such  class  has  access  control  lists  enumerating	who  may  transmit
       (xmt-*.acl)  or	subscribe  to  that particular class.  Subscriptions may be restricted either absolutely (sub-*.acl files), or by instance
       restrictions.  iws-*.acl files control subscriptions to wildcarded instances.  iui-*.acl files control subscriptions to instances which are
       not  the  Kerberos  principal  identity of the subscriber.  If an access control list of a given type is absent, there is no restriction of
       that type on the class, except that any notices of the class must be authenticated.   The  class  registry  lists  all  classes	which  are
       restricted.

FILES

       /etc/zephyr/acl/class-registry.acl:
		 List of classes which are restricted

       /etc/zephyr/acl/iws-*.acl:
		 Access Control Lists for instance-wildcard restrictions

       /etc/zephyr/acl/iui-*.acl:
		 Access Control Lists for instance-identity restrictions

       /etc/zephyr/acl/sub-*.acl:
		 Access Control Lists for subscribing

       /etc/zephyr/acl/xmt-*.acl:
		 Access Control Lists for transmitting

       /etc/zephyr/srvtab:
		 Kerberos 4 Service keys

       /etc/zephyr/krb5.keytab:
		 Kerberos V Service keys

       /etc/zephyr/ztkts:
		 Current Kerberos tickets for exchange with other servers

       /var/tmp/zephyr.db:
		 File containing an ASCII dump of the database.

BUGS

       The  current  implementation  of the Zephyr server (zephyrd(8)) makes no distinction between realm-announced, net-visible and net-announced
       exposure levels.

SEE ALSO

       zephyr(1), zhm(8), kerberosintro(1), hesiod(3), access_control_lists(?), syslog(3)
       Athena Technical Plan, Sections E.4.1 (Zephyr Notification Service) and E.2.1 (Kerberos Authentication and Authorization System)

AUTHOR

       John T. Kohl, MIT Project Athena and Digital Equipment Corporation

RESTRICTIONS

       Copyright (c) 1987,1988 by the Massachusetts Institute of Technology.  All Rights Reserved.
       zephyr(1) specifies the terms and conditions for redistribution.

MIT Project Athena						   July 1, 1988 							ZEPHYRD(8)