4.3BSD-UWisc/man/cat8/timed.8

TIMED(8)            UNIX Programmer's Manual             TIMED(8)



NAME
     timed - time server daemon

SYNOPSIS
     /etc/timed [ -t ] [ -M ] [ -n network ] [ -i network ]

DESCRIPTION
     _T_i_m_e_d is the time server daemon and is normally  invoked  at
     boot  time  from  the _r_c(8) file. It synchronizes the host's
     time with the time of other machines in a local area network
     running  _t_i_m_e_d(8).   These  time  servers will slow down the
     clocks of some machines and speed up the clocks of others to
     bring them to the average network time.  The average network
     time is computed  from  measurements  of  clock  differences
     using the ICMP timestamp request message.

     The service provided by _t_i_m_e_d is based   on  a  master-slave
     scheme.   When _t_i_m_e_d(8) is started on a machine, it asks the
     master for the network time and sets  the  host's  clock  to
     that  time.  After that, it accepts synchronization messages
     periodically sent by the master and calls _a_d_j_t_i_m_e(2) to per-
     form the needed corrections on the host's clock.

     It also communicates with _d_a_t_e(1) in order to set  the  date
     globally,  and  with _t_i_m_e_d_c(8), a timed control program.  If
     the machine running the master crashes, then the slaves will
     elect  a  new  master  from among slaves running with the -M
     flag.  A _t_i_m_e_d running without the -M  flag  will  remain  a
     slave.   The  -t flag enables _t_i_m_e_d to trace the messages it
     receives in the file  /usr/adm/timed.log.   Tracing  can  be
     turned  on  or off by the program _t_i_m_e_d_c(8).  _T_i_m_e_d normally
     checks for a master time server on each network to which  it
     is  connected,  except  as modified by the options described
     below.  It will request  synchronization  service  from  the
     first  master  server located.  If permitted by the -M flag,
     it will provide synchronization service on any attached net-
     works  on which no current master server was detected.  Such
     a server propagates the time computed by the top-level  mas-
     ter.   The  -n flag, followed by the name of a network which
     the host is connected to (see  _n_e_t_w_o_r_k_s(5)),  overrides  the
     default choice of the network addresses made by the program.
     Each time the -n flag appears, that network name is added to
     a  list  of valid networks.  All other networks are ignored.
     The -i flag, followed by the name of a network to which  the
     host  is  connected (see _n_e_t_w_o_r_k_s(5)), overrides the default
     choice of the network addresses made by the  program.   Each
     time  the  -i  flag appears, that network name is added to a
     list of networks to ignore.  All other networks are used  by
     the  time  daemon.   The  -n and -i flags are meaningless if
     used together.





Printed 12/27/86          May 28, 1986                          1






TIMED(8)            UNIX Programmer's Manual             TIMED(8)



FILES
     /usr/adm/timed.log           tracing file for timed
     /usr/adm/timed.masterlog     log file for master timed

SEE ALSO
     date(1), adjtime(2), gettimeofday(2), icmp(4P), timedc(8),
     _T_S_P: _T_h_e _T_i_m_e _S_y_n_c_h_r_o_n_i_z_a_t_i_o_n _P_r_o_t_o_c_o_l _f_o_r _U_N_I_X  _4._3_B_S_D,  R.
     Gusella and S. Zatti















































Printed 12/27/86          May 28, 1986                          2