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ZEPHYR(1)						      General Commands Manual							 ZEPHYR(1)

zephyr - Zephyr Notification Service DESCRIPTION
Zephyr is a notice transport and delivery system developed at MIT which runs under 4.3BSD Unix. A Notice Transport and Delivery system is a method of getting small quantities of time sensitive information efficiently from one client (or server) on a network to another. The object is to accomplish this with the highest possible fan-out (i.e., client to server ratio) while maintaining both network and server performance. Zephyr is a multi-cast notice transport and delivery system based upon an authenti- cated datagram protocol. Localized Zephyr servers provide routing, queueing and dispatching services to clients which communicate with them via the Zephyr Client Library. Two special purpose Zephyr clients, the WindowGram client and the HostManager client provide user and client host communication support. Zephyrd(8) servers run on designated server machines. These servers maintain a database of subscriptions and locations for every user using Zephyr. The servers stay in contact with one another, and provide a reliable backup system (via duplication) in the event of network failures. Each client machine on the network runs a zhm(8) HostManager client program which is the link between the Zephyr servers and the users. User programs send notices to the HostManager, and the HostManager forwards these notices to the nearest server for action. The HostMan- ager is responsible for ensuring that the notices reach a server, and for finding a new one if its server fails to respond. Each user on the network usually runs a WindowGram client program automatically upon login. Zwgc(1) displays notices to the user, and han- dles user responses. Only notices to which the user has subscribed will be sent to the WindowGram client. Subscriptions are handled through the zctl(1) program. This program allows the user to add or delete subscriptions from Zephyr, to add the subscriptions to a file, and to perform other miscellaneous functions. SEE ALSO
kerberosintro(1) zaway(1), zctl(1), zleave(1), zlocate(1), znol(1), zwgc(1), zwrite(1), zmailnotify(1) zhm(8), zephyrd(8), zinit(8), zstat(8), zpopnotify(8), zshutdown_notify(8), syslogd(8) Project Athena Technical Plan Section E.4.1, `Zephyr Notification Service' AUTHORS
Tony Della Fera (MIT-Project Athena, DEC), Mark W. Eichin (MIT-Project Athena), Robert S. French (MIT-Project Athena), David C. Jedlinsky (MIT-Project Athena), John T. Kohl (MIT-Project Athena, DEC), William E. Sommerfeld (MIT-Project Athena). RESTRICTIONS
Copyright (c) 1987,1988,1989 by the Massachusetts Institute of Technology. All Rights Reserved. Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, pro- vided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in sup- porting documentation, and that the name of the Massachusetts Institute of Technology not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. M.I.T. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL M.I.T. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. MIT Project Athena July 1, 1988 ZEPHYR(1)

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

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)
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