Hi mschlenker,
Thank you for your suggestions. unfortunately it did not work:
root@rss:/home/admin# systemctl status check-mk-agent.socket
● check-mk-agent.socket - Local Checkmk agent socket
Loaded: loaded (/lib/systemd/system/check-mk-agent.socket; enabled; vendor preset: enabled)
Active: active (listening) since Mon 2022-05-30 18:46:54 UTC; 12min ago
Triggers: ● check-mk-agent@0.service
Listen: /run/check-mk-agent.socket (Stream)
Accepted: 0; Connected: 0;
Tasks: 0 (limit: 1066)
Memory: 52.0K
CGroup: /system.slice/check-mk-agent.socket
May 30 18:46:54 rss systemd[1]: Starting Local Checkmk agent socket.
May 30 18:46:54 rss systemd[1]: Listening on Local Checkmk agent socket.
root@rss:/home/admin# systemctl stop check-mk-agent.socket
root@rss:/home/admin# systemctl disable check-mk-agent.socket
Removed /etc/systemd/system/sockets.target.wants/check-mk-agent.socket.
root@rss:/home/admin# ls
check-mk-agent_2.1.0-1_all.deb index.html
root@rss:/home/admin# dpkg -i check-mk-agent_2.1.0-1_all.deb
(Reading database ... 110354 files and directories currently installed.)
Preparing to unpack check-mk-agent_2.1.0-1_all.deb ...
Removing systemd units: check-mk-agent@.service, check-mk-agent-async.service, cmk-agent-ctl-daemon.service, check-mk-agent.socket
Unpacking check-mk-agent (2.1.0-1) over (2.1.0-1) ...
Setting up check-mk-agent (2.1.0-1) ...
Deploying systemd units: check-mk-agent@.service check-mk-agent-async.service cmk-agent-ctl-daemon.service check-mk-agent.socket
Deployed systemd
Creating/updating cmk-agent user account ...
Activating systemd unit 'check-mk-agent-async.service'...
Activating systemd unit 'cmk-agent-ctl-daemon.service'...
Activating systemd unit 'check-mk-agent.socket'...
Created symlink /etc/systemd/system/sockets.target.wants/check-mk-agent.socket → /lib/systemd/system/check-mk-agent.socket.
root@rss:/home/admin# ss -tulpn | grep 6556
tcp LISTEN 0 4096 *:6556 *:* users:(("systemd",pid=1,fd=86))