NAME

       remctl - Remote execution tool

SYNOPSIS

       remctl [-dhv] [-b source-ip] [-p port] [-s service]
           [-t timeout] host command [subcommand [parameters ...]]

DESCRIPTION

       remctl is a program that allows a user to execute commands remotely on a server that is running the
       remctld daemon.  remctl does not interpret the commands given to it.  It passes them to the server and
       displays the return message.  The commands must be defined on the server-side before a remctl client can
       execute them, and the user running remctl must be authorized to execute the particular command on the
       server.

       Access to remote commands is authenticated via Kerberos GSS-API, so a user must have a ticket granting
       ticket to use remctl.  All transmissions to and from the remctld server are encrypted using GSS-API's
       security layer.

       host is the hostname of the target server.  command and subcommand together specify the command to run
       and correspond to the command names in the configuration file on the server.  parameters are any
       additional command-line parameters to pass to the remote command.

OPTIONS

       The start of each option description is annotated with the version of remctl in which that option was
       added with its current meaning.

       -b source-ip
           [3.0] When connecting to the remote remctl server, use source-ip as the source IP address.  This can
           be useful on multihomed systems where the remctl connections need to be made over a particular
           network.  source-ip must be an IP address, not a hostname, and can be either an IPv4 or IPv6 address
           (assuming IPv6 is supported).

       -d  [1.10] Turn on extra debugging output of the client-server interaction.

       -h  [1.10] Show a brief usage message and then exit.

       -p port
           [1.0] Connect to the server on port.  If this option isn't given, the client first tries the
           registered remctl port (4373) and then falls back on the legacy port (4444) if that fails.

       -s service
           [1.0] Authenticate to the server with a service ticket for service rather than the default server
           identity of host/hostname.  This may be necessary with, for instance, a server where remctld is not
           running as root.

       -t timeout
           [3.16] Set the timeout for all network operations to timeout (in seconds).

           This is a timeout on network activity, not on a complete operation; for example, a timeout of ten
           seconds just requires that the server send some data at least every ten seconds.  If the server sends
           only tiny amounts of data at a time, the complete operation could take much longer without triggering
           the timeout.

       -v  [1.10] Print the version of remctl and exit.

EXIT STATUS

       remctl will exit with the exit status returned by the remote command.  If some network or authentication
       error occurred and remctl was unable to run the remote command or retrieve its exit status, or if remctl
       was called with invalid arguments, remctl will exit with status 1.

EXAMPLES

       Release an AFS volume called ls.tripwire:

           remctl lsdb afs release ls.tripwire

COMPATIBILITY

       The default port was changed to the IANA-registered port of 4373 in version 2.11.

       Support for IPv6 was added in version 2.4.

CAVEATS

       If no principal is specified with -s, remctl canonicalizes the server host name using DNS before
       connecting.  This ensures that the network connection and the GSS-API authentication use the same server
       name even if some common DNS-based load-balancing schemes are in use.  To disable this canonicalization,
       specify the server principal using -s.

       The default behavior, when the port is not specified, of trying 4373 and falling back to 4444 will be
       removed in a future version of remctl in favor of using the "remctl" service in /etc/services if set and
       then falling back on only 4373.  4444 was the poorly-chosen original remctl port and should be phased
       out.

       When using Heimdal with triple-DES keys and talking to old servers that only speak version one of the
       remctl protocol, remctl may have problems with MIC verification.  This doesn't affect new clients and
       servers since the version two protocol doesn't use MICs.  If you are using Heimdal and run into MIC
       verification problems, see the COMPATIBILITY section of gssapi(3).

NOTES

       The remctl port number, 4373, was derived by tracing the diagonals of a QWERTY keyboard up from the
       letters "remc" to the number row.

AUTHOR

       remctl was originally written by Anton Ushakov.  Updates and current maintenance are done by Russ Allbery
       <eagle@eyrie.org>.

COPYRIGHT AND LICENSE

       Copyright 2018 Russ Allbery <eagle@eyrie.org>

       Copyright 2002-2011, 2014 The Board of Trustees of the Leland Stanford Junior University

       Copying and distribution of this file, with or without modification, are permitted in any medium without
       royalty provided the copyright notice and this notice are preserved.  This file is offered as-is, without
       any warranty.

       SPDX-License-Identifier: FSFAP

SEE ALSO

       kinit(1), remctld(8)

       The current version of this program is available from its web page at
       <https://www.eyrie.org/~eagle/software/remctl/>.