Ubuntu Manpage: rpcbind — universal addresses to RPC program number mapper

Provided by: rpcbind_0.2.3-0.6ubuntu0.18.04.4_amd64

NAME

       rpcbind — universal addresses to RPC program number mapper

SYNOPSIS

       rpcbind [-adhiLlsr]

DESCRIPTION

       The  rpcbind  utility is a server that converts RPC program numbers into universal addresses.  It must be
       running on the host to be able to make RPC calls on a server on that machine.

       When an RPC service is started, it tells rpcbind the address at  which  it  is  listening,  and  the  RPC
       program  numbers  it  is  prepared to serve.  When a client wishes to make an RPC call to a given program
       number, it first contacts rpcbind on the server machine to  determine  the  address  where  RPC  requests
       should be sent.

       The  rpcbind  utility should be started before any other RPC service.  Normally, standard RPC servers are
       started by port monitors, so rpcbind must be started before port monitors are invoked.

       When rpcbind is started, it checks that certain name-to-address translation-calls function correctly.  If
       they fail, the network configuration databases may  be  corrupt.   Since  RPC  services  cannot  function
       correctly in this situation, rpcbind reports the condition and terminates.

       The rpcbind utility can only be started by the super-user.

OPTIONS

-a When debugging (-d), do an abort on errors.

-d Run in debug mode. In this mode, rpcbind will log additional information during operation, and
will abort on certain errors if -a is also specified. With this option, the name-to-address
translation consistency checks are shown in detail.

-f Do not fork and become a background process.

-h Specify specific IP addresses to bind to for UDP requests. This option may be specified multiple
times and is typically necessary when running on a multi-homed host. If no -h option is
specified, rpcbind will bind to INADDR_ANY, which could lead to problems on a multi-homed host
due to rpcbind returning a UDP packet from a different IP address than it was sent to. Note that
when specifying IP addresses with -h, rpcbind will automatically add 127.0.0.1 and if IPv6 is
enabled, ::1 to the list.

-i “Insecure” mode. Allow calls to SET and UNSET from any host. Normally rpcbind accepts these
requests only from the loopback interface for security reasons. This change is necessary for
programs that were compiled with earlier versions of the rpc library and do not make those
requests using the loopback interface.

-l Turn on libwrap connection logging.

-s Cause rpcbind to change to the user daemon as soon as possible. This causes rpcbind to use non-
privileged ports for outgoing connections, preventing non-privileged clients from using rpcbind
to connect to services from a privileged port.

-w Cause rpcbind to do a "warm start" by read a state file when rpcbind starts up. The state file is
created when rpcbind terminates.

-r Turn on remote calls. Cause rpcbind to open up random listening ports. Note that rpcinfo need
this feature turned on for work properly. Ubuntu note: to retain backwards compatibility with
existing behavior, in releases Xenial and Bionic, the default for this is enabled, so remote
calls are turned on by default. To change the default to disabled, define the variable
-RPCBIND_RMTCALL_DEFAULT_DISABLED (its value does not matter, it only needs to be defined) in
either of the config files, /etc/default/rpcbind or /etc/rpcbind.conf. This will work only if the
service is started by systemd; this will not work if the service is started by upstart. In Focal
and later, the remote calls default is disabled, and the variable is ignored.

NOTES

       All RPC servers must be restarted if rpcbind is restarted.

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