1in.rwhod(1M)            System Administration Commands            in.rwhod(1M)
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NAME

6       in.rwhod, rwhod - system status server
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SYNOPSIS

9       /usr/sbin/in.rwhod [-m [ttl]]
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DESCRIPTION

13       in.rwhod is the server which maintains the database used by the rwho(1)
14       and ruptime(1) programs.  Its operation is predicated on the ability to
15       broadcast or multicast messages on a network.
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18       in.rwhod  operates  as  both a producer and consumer of status informa‐
19       tion. As a producer of information it periodically queries the state of
20       the system and constructs status messages which are broadcast or multi‐
21       cast on a network. As a consumer of information, it listens  for  other
22       in.rwhod servers' status messages, validating them, then recording them
23       in a collection of files located in the directory /var/spool/rwho.
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26       The rwho server transmits and receives messages at the  port  indicated
27       in  the  rwho service specification, see services(4). The messages sent
28       and received are defined in /usr/include/protocols/rwhod.h and  are  of
29       the form:
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31         struct  outmp {
32                 char     out_line[8];   /* tty name */
33                 char     out_name[8];   /* user id */
34                 long     out_time;      /* time on */
35         };
36         struct  whod {
37                 char     wd_vers;
38                 char     wd_type;
39                 char     wd_fill[2];
40                 int      wd_sendtime;
41                 int      wd_recvtime;
42                 char     wd_hostname[32];
43                 int      wd_loadav[3];
44                 int      wd_boottime;
45                 struct   whoent {
46                          struct   outmp we_utmp;
47                          int      we_idle;
48              } wd_we[1024 / sizeof (struct whoent)];
49          };
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54       All  fields  are converted to network byte order prior to transmission.
55       The load averages are as calculated by the w(1) program, and  represent
56       load  averages  over  the  1,  5,  and  15  minute intervals prior to a
57       server's transmission.  The host name included is that returned by  the
58       uname(2)  system  call.  The  array  at the end of the message contains
59       information about the users who are logged in to the  sending  machine.
60       This  information  includes the contents of the utmpx(4) entry for each
61       non-idle terminal line and a value indicating the time since a  charac‐
62       ter was last received on the terminal line.
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65       Messages  received  by the rwho server are discarded unless they origi‐
66       nated at a rwho server's port.  In addition, if  the  host's  name,  as
67       specified  in  the  message, contains any unprintable ASCII characters,
68       the message is discarded.  Valid  messages  received  by  in.rwhod  are
69       placed  in  files named whod.hostname in the directory /var/spool/rwho.
70       These files contain  only  the  most  recent  message,  in  the  format
71       described above.
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74       Status messages are generated approximately once every 3 minutes.
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OPTIONS

77       The following options are supported:
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79       -m [ ttl ]    Use  the  rwho   IP  multicast  address  (224.0.1.3) when
80                     transmitting. Receive announcements both on  this  multi‐
81                     cast address and on the  IP broadcast address. If  ttl is
82                     not specified  in.rwhod multicasts on all interfaces  but
83                     with  the   IP  TimeToLive set to 1 (that is, packets are
84                     not forwarded by multicast routers.) If  ttl is specified
85                     in.rwhod only transmits packets on one interface and set‐
86                     ting the  IP TimeToLive to the specified  ttl.
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FILES

90       /var/spool/rwho/whod.*    information about other machines
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ATTRIBUTES

94       See attributes(5) for descriptions of the following attributes:
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99       ┌─────────────────────────────┬─────────────────────────────┐
100       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
101       ├─────────────────────────────┼─────────────────────────────┤
102       │Availability                 │SUNWrcmds                    │
103       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

106       ruptime(1),   rwho(1),   w(1),   uname(2),    services(4),    utmpx(4),
107       attributes(5)
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WARNINGS

110       This  service  can cause network performance problems when used by sev‐
111       eral hosts on the network. It is not run at most sites by  default.  If
112       used, include the -m multicast option.
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NOTES

115       This  service takes up progressively more network bandwidth as the num‐
116       ber of hosts on the local net increases.  For large networks, the  cost
117       becomes prohibitive.
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120       in.rwhod should relay status information between networks. People often
121       interpret the server dying as a machine going down.
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125SunOS 5.11                        8 Dec 2001                      in.rwhod(1M)
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