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

       rpcapd - capture daemon to be controlled by a remote libpcap

       rpcapd [ -b address ] [ -p port ] [ -4 ] [ -l host_list ]
               [ -a host,port ] [ -n ] [ -v ] [ -d ] [ -i ]
               [ -D ] [ -s config_file ] [ -f config_file ] [ -S ]
               [ -K ssl_keyfile ] [ -X ssl_certfile ] [ -C ]

       Rpcapd is a daemon (Unix) or service (Win32) that allows the capture
       and filter part of libpcap to be run on a remote system.

       Rpcapd can run in two modes: passive mode (default) and active mode.

       In passive mode, the client (e.g., a network sniffer) connects to
       rpcapd.  The client then sends the appropriate commands to rpcapd to
       start the capture.

       In active mode, rpcapd tries to establish a connection toward the
       client (e.g., a network sniffer). The client then sends the appropriate
       commands to rpcapd to start the capture.

       Active mode is useful in case rpcapd is run behind a firewall and
       cannot receive connections from the external world. In this case,
       rpcapd can be configured to establish the connection to a given host,
       which has to be configured in order to wait for that connection. After
       establishing the connection, the protocol continues its job in almost
       the same way in both active and passive mode.

Configuration file
       The user can create a configuration file in the same directory as the
       executable, and put the configuration commands in there. In order for
       rpcapd to execute the commands, it needs to be restarted on Win32, i.e.
       the configuration file is parsed only at the beginning. The UNIX
       version of rpcapd will reread the configuration file upon receiving a
       HUP signal. In that case, all the existing connections remain in place,
       while the new connections will be created according to the new

       In case a user does not want to create the configuration file manually,
       they can launch rpcapd with the desired flags plus -s filename.  Rpcapd
       will parse all the parameters and save them into the specified
       configuration file.

Installing rpcapd on Win32
       The remote daemon is installed automatically when installing WinPcap.
       The installation process places the rpcapd executable file into the
       WinPcap folder.  This file can be executed either from the command
       line, or as a service.  For instance, the installation process updates
       the list of available services list and it creates a new item (Remote
       Packet Capture Protocol v.0 (experimental)).  To avoid security
       problems, the service is inactive and it has to be started manually
       (control panel - administrative tools - services - start).

       The service has a set of "standard" parameters, i.e. it is launched
       with the -d flag (in order to make it run as a service) and the -f
       rpcapd.ini flag.

Starting rpcapd on Win32
       The rpcapd executable can be launched directly, i.e.  it can run in the
       foreground as well (not as a daemon/service).  The procedure is quite
       simple: you have to invoke the executable from the command line with
       all the requested parameters except for the -d flag.  The capture
       server will start in the foreground.

Installing rpcapd on Unix-like systems

Starting rpcapd on Unix-like systems
       rpcapd needs sufficient privileges to perform packet capture, e.g.  run
       as root or be owned by root and have suid set. Most operating systems
       provide more elegant solutions when run as user than the above
       solutions, all of them different.

       If your system supports systemd(1) and the corresponding rpcapd.socket
       and rpcapd@.service service files have been installed, the rpcapd
       service can be enabled by enabling the rpcapd.socket unit.

       If your system supports launchd(8) and the org.tcpdump.rpcapd.plist
       file has been installed, the rpcapd service can be enabled by loading
       the org.tcpdump.rpcapd service.

       If your system supports inetd(8) and the rpcapd.inetd.conf entry has
       been added to inetd.conf(5), the rpcapd service can be enabled by
       telling inetd to reread its configuration file.

       If your system supports xinetd(8) and the rpcapd.xinetd.conf entry has
       been added to xinetd.conf(5), the rpcapd service can be enabled by
       telling xinetd to reread its configuration file.

       -b address
              Bind to the IP address specified by address (either numeric or
              literal).  By default, rpcapd binds to all local IPv4 and IPv6

       -p port
              Bind to the port specified by port.  By default, rpcapd binds to
              port 2002.

       -4     Listen only on IPv4 addresses.  By default, rpcapd listens on
              both IPv4 and IPv6 addresses.

       -l host_list
              Only allow hosts specified in the host_list argument to connect
              to this server.  host_list is a list of host names or IP
              addresses, separated by commas.  We suggest that you use host
              names rather than literal IP addresses in order to avoid
              problems with different address families.

       -n     Permit NULL authentication (usually used with -l).

       -a host,port
              Run in active mode, connecting to host host on port port.  In
              case port is omitted, the default port (2003) is used.

       -v     Run in active mode only; by default, if -a is specified, rpcapd
              it accepts passive connections as well.

       -d     Run in daemon mode (UNIX only) or as a service (Win32 only).
              Warning (Win32): this flag is specified automatically when the
              service is started from the control panel.

       -i     Run in inetd mode (UNIX only).

       -D     Log debugging messages.

       -s config_file
              Save the current configuration to config_file in the format
              specified by rpcapd-config(5).

       -f config_file
              Load the current configuration from config_file in the format
              specified by rpcapd-config(5) and ignore all flags specified on
              the command line.

       -h     Print this help screen.

       If rpcapd was compiled with SSL support, the following options are also

       -S     Require that SSL be used on connections.

       -C     With SSL enabled, XXX - I'm not sure how *fetching* the list of
              compression mechanisms does anything to compression.

       -S     ssl_keyfile With SSL enabled, use ssl_keyfile as the SSL key

       -X     ssl_certfile With SSL enabled, use ssl_certfile as the SSL
              certificate file.

       pcap(3), rpcapd-config(5)

                                20 January 2023                      RPCAPD(8)