For comparison, on my Debian Bookworm (aka "testing" but in hard freeze and full freeze in a few days I think, stable release in june) here... ...$ lsmod|

For comparison, on my Debian Bookworm (aka "testing" but in hard freeze and full freeze in a few days I think, stable release in june) here... ...$ lsmod|grep nf_table (tried without any just to make sure) ...$ unshare -U -m -n -r unshare: unshare: failed: Operation not permitted ...$ /sbin/nft add table inet filter Error: Could not process rule: Operation not permitted add table inet filter ^^^^^^^^^^^^^^^^^^^^^^ root # cat /proc/sys/kernel/unprivileged_userns_clone 0