Why nfsd version 4 disappear from rpcinfo output?

On Solaris, I enable nfs4 with those options vim /etc/default/nfs # Sets the minimum version of the NFS protocol that will be registered # and offered by the server. The default is 2. NFS_SERVER_VERSMIN=4 # Sets the maximum version of the NFS protocol that will be registered # and offered by the server. The default is 4. NFS_SERVER_VERSMAX=4 I try the same on Linux (the syntax is different) RPC_NFSD_OPTS="-N 2 -N 3" Nfs mount works on all hosts. But very strange thing happen with rpc On Linux rpcinfo -t 192.168.0.2 nfs 192.168.0.2: RPC: Program not registered On Solaris rpcinfo -t 192.168.201.3 nfs program 100003 version 4 ready and waiting Why rpc don't register nfs4 on Linux? Linux distro is Slackware 15.0 kernel version 6.11.10