Brief: I bought mini laptop for workstation purposes (on Intel CPU and GPU), and I decided to try Clear Linux. I’m not a sysadmin, so after the transition from Ubuntu I need answers.
I have a fresh installation on Clear Linux and try to minimal properly setup it. I tried to turn off all unnecessary services and expected that I would not see the open ports associated with them.
And when I masked the
sudo systemctl mask cupsd, this is exactly what happened - no any LISTEN ports for that service.
But why it doesn’t work with ssh/sshd?
user@pc~ $ sudo systemctl sshd * sshd.service Loaded: masked (Reason: Unit sshd.service is masked.) Active: inactive (dead) user@pc~ $ sudo lsof -P -i -n COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME systemd 1 root 50u IPv6 17039 0t0 TCP *:22 (LISTEN) system-r 361 systemd-resolve 12u IPv4 21534 0t0 UDP 127.0.0.53:53 system-r 361 systemd-resolve 13u IPv4 21535 0t0 TCP 127.0.0.53:53 (LISTEN)
As far I know, it means active ssh-server/service for external connections that binded *:22 on any interfaces (assigned IPs, and external hosts can connect to me)
Whether it’s a part of non-disable internal system design of Clear Linux* or it does by other way. And why does sshd.service is exist, if ssh(22) is still running?
Thanx for any info.