NFS Version 4 Only

Use Debian 12

apt update && sudo apt install nfs-kernel-server
systemctl status nfs-server
ss -lntp | grep 2049

nfs-v4-only.sh

#!/bin/bash
set -eu

cat /proc/fs/nfsd/versions
sed 's/^# vers3=y$/vers3=n/g' /etc/nfs.conf
systemctl restart nfs-kernel-server
cat /proc/fs/nfsd/versions

alt-for-older.sh

sed -i 's/^NEED_STATD=*/NEED_STATD="no"/g' /etc/default/nfs-common
sed -i 's/^NEED_IDMAPD=*/NEED_IDMAPD="yes"/g' /etc/default/nfs-common
sed -i 's/^RPCNFSDOPTS=*/RPCNFSDOPTS="-N 2 -N 3"/g'  /etc/default/nfs-kernel-server
sed -i 's/^RPCMOUNTDOPTS=*/RPCMOUNTDOPTS="--manage-gids -N 2 -N 3"/g' /etc/default/nfs-common

sudo systemctl mask rpcbind.service
sudo systemctl mask rpcbind.socket
# sudo systemctl unmask rpcbind.service
# sudo systemctl unmask rpcbind.socket

cat /proc/fs/nfsd/versions

More stuff Old

Enable verion 4 only by disabling 2 and 3 (2 is already disabled on modern os) - https://wiki.debian.org/NFSServerSetup - https://help.ubuntu.com/community/NFSv4Howto

/etc/default/nfs-kernel-server # update

# RPCMOUNTDOPTS="--manage-gids"
RPCMOUNTDOPTS="--manage-gids -N 2 -N 3"
RPCNFSDOPTS="-N 2 -N 3"

/etc/default/nfs-common # add

NEED_STATD="no"
NEED_IDMAPD="yes"

sudo systemctl mask rpcbind.service
sudo systemctl mask rpcbind.socket
sudo cat /proc/fs/nfsd/versions
sudo systemctl restart nfs-server
sudo cat /proc/fs/nfsd/versions

showmount -e nas

does not work now

and all traffic goes over 2049 unencrypted with only ip address access restrictions. Very simple, very fast.

/etc/exports

/101f8f6a-e761-11eb-8e23-afa707071684    192.168.1.10(rw,sync,no_subtree_check,insecure,root_squash)

/etc/fstab

nfshost:/101f8f6a-e761-11eb-8e23-afa707071684 /opt/localnfshare nfs4  _netdev,auto  0  0