forbid_outside_nodes.sh

#!/usr/sbin/nft -f

# to list rules: nft list table t
# to remove rules: nft flush table t

define nodes = { 200.69.141.134, 52.40.149.71, 45.32.83.15 }

add table t
add chain ip t input { type filter hook input priority 0; policy accept; }
add rule t input ip daddr $nodes drop
add chain ip t output { type filter hook output priority 0; policy accept; }
add rule t output ip daddr $nodes drop

#