Ubuntu 20.04 LTS SSH 문제

*sudo 제외 

apt install network-tools


apt update && sudo apt upgrade -y
apt install openssh-server -y


sudo systemctl enable --now ssh 할 시 
Synchronizing state of ssh.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable ssh
System has not been booted with systemd as init system (PID 1). Can't operate.
Failed to connect to bus: Host is down 라는 오류가 뜸 
이건 systemctl이 없다고 하는건데 해결 방법은 

apt-get install systemd

"service 서비스명 start"
"ser


service ssh start #ssh 시작
service enable ssh #시스템 시작시 자동 실행

ufw allow ssh #방화벽 시스템에서 ssh포트 열기 
#오류가 뜬다면 apt-get install --reinstall linux-modules-5.4.0-42-generic 
#apt-get install --reinstall iptables
#그래도 오류가 뜬다 Perhaps iptables or your kernel needs to be upgraded.
#Skipping adding existing rule