The rpcbind in WRlinux5.0.1 have an option -p to specify the random_port. While in the rpcbind's usage, it dose not print the -p option. Customer complain that it should add the right usage. The -p options and the random_port is add by the rpcbind_add_option_to_fix_port_number.patch. It didn't update the rpcbind's usage. See the function parseargs in the build/rpcbind-0.2.0-r6/rpcbind-0.2.0/src/rpcbind.c . And the build/rpcbind-0.2.0-r6/rpcbind-0.2.0/patches/rpcbind_add_option_to_fix_port_number.patch .