We should use:
nsenter --net=netnsPath -- -F some_command
instend of:
nsenter -n netnsPath -- -F some_command
Because "nsenter -n netnsPath" get an error output:
# nsenter -n /proc/67197/ns/net ip addr
nsenter: neither filename nor target pid supplied for ns/net
If we really want use -n, we need to use -n in such format:
# sudo nsenter -n/proc/67197/ns/net ip addr