CMK 2. 2. ” failed with this error: "Request failed with code 500 Internal Server Error: Internal Server Error" The registration then aborts, since we cannot continue without knowing the correct port. 0. CMK version: 2. check_mk agent runs on top of xinetd service in Linux. This query is attempted both with and both queries fail, the controller aborts, otherwise, the result of the first sucessful query is. CMK 2. sh script. Ping works, Agent reports Communication Failed: timed out. The agent control use the port 8000 for communication. CMK 2. Wie Sie den Agenten nutzen, erfahren Sie hier. service: Scheduled restart job, restart counter is at 2. But if cmk-agent-ctl cannot be started, access fails. Distribute below files from new baked agent to all agents that were baked with expired certificate. For Debian remove the cmk-agent and purge the configuration, than reinstall the agent, this purges the xinetd configuration. TLD -i SITE-NAME -U USERNAME This worked perfectly fine in CMK 2. 1. If you want to use the agent in legacy mode, you need to disable cmk-agent-ctl in bakery rules. 0 did not yet use TLS, so port 8000 didn’t need to be exposed back then. 2 system. The folder /var/lib/cmk-agent was missing on my SUSE Linux Enterprise Micro 5. deb Monitored System (Host): Checkmk Agent version: 2. 488899 +01:00] INFO [cmk_agent_ctl] srcmain. XXX. de --server monitor. cme and I’m no longer able to register new hosts with an automation user “cmkautomation” that I created a while ago (with role “agent_registration”). Unfortunately, the problem remains: C:WINDOWSsystem32>"C:Program Files (x86)checkmkservicecmk-agent-ctl. Diese werden auch als aktive Checks bezeichnet. Ikkarus13 (Sascha Kunimünch) May 30, 2022, 8:00am 1. To register the agent, I ran: sudo cmk-agent-ctl register --hostname localhost --server localhost:8001 --site cmk --user cmkadmin That gives: > sudo cmk-agent-ctl status Version: 2. Yes I did use the” cmk-agent-ctl register command, after that I got this message. DOMAIN. agent_pairing") to their role. 0-1_all. Agent pairing; Read access to all hosts and foldersSince Checkmk version 2. Run communication test. In your case. For more information try --helpcmk-agent-ctl register --server cmkserver:443 --trust-cert --site cmksite --user username --password password --hostname monitoringhost On Debian 11 if got the following outputTo register the agent, I ran: sudo cmk-agent-ctl register --hostname localhost --server localhost:8001 --site cmk --user cmkadmin That gives: > sudo cmk-agent-ctl status Version: 2. exe register --hostname xxx --server checkmk:8000 --site monitoring --user automation --… Hi, in the register-command use --server checkmk without the port, maybe there is a formatting problem with that. 10. 0p10 Agent socket: operational IP allowlist: any Connection: localhost:8001/cmk UUID: 186f71b9-8d6f-41c6-be44-bb1f7c23ae7b Local: Connection. Output of “cmk --debug -vvn hostname”: (If it is a problem with checks or plugins) I have registered over 100 hosts successfull but something is wrong with this one when I use that command: & 'C:Program Files (x86)checkmkservicecmk-agent-ctl. 0) master 1. 0 2. 0 2. You have three options here: Make the REST API call work. hinbekommen habe ich es nicht. If it is systemd please give us the output of systemctl --version. In order to register at a Checkmk site, the agent controller ( cmk-agent-ctl) needs to know, among others, the name of the server where the site is running and a. 0 did not yet use TLS, so port 8000 didn’t need to be exposed back then. Checkmk. cd /etc sudo rm -r check_mk cd /var/lib sudo rm -r check_mk_agent sudo rm -r cmk-agent cd /usr/lib sudo rm -r check_mk_agent sudo systemctl daemon-reload. com. 2. cmk-agent-ctl register -v -H HOSTNAME -P 'PASSWORD' -s SUBDOMAIN. g. I dont know why this folder could not be created during cmk agent installation from the cmk-agent-useradd. As suggested in another post i read i checked:-that port 8000 is open-omd config show | grep AGENT_RECEIVER show port 8000The registration then aborts, since we cannot continue without knowing the correct port. 0. Finally, in Bake agent packages, activate. 0. The folder /var/lib/cmk-agent was missing on my SUSE Linux Enterprise Micro 5. OS version: Ubuntu Server. socket → /lib/systemd/system/check-mk-agent. Dear friends of Checkmk, the new stable release 2. this is initiated by the cloud host contacting CMK server behind our office. 1. 1 does not exist. Dann hast du die Herangehensweise schon gefunden, wenn man die Zertifikate noch nicht im Griff hat. 6 I have an external cloud host that I would like to monitor with in-house CMK server. serviceSo now you must de-register, on the host: cmk-agent-ctl delete-all --enable-insecure-connections Then on the CMK server: Properties of host , then menu entry Host > Remove TLS registration Afterwards connections should work albeit insecure. g. NOTE: A registered host will refuse all unencrypted connections. If you forward port 9800 to 8000 then you also have to use port 9800 in your register command. Password for user ‘cmkadmin’: Successfully registered agent of host “monitor2” for deployment. (We used cmk-agent-ctl proxy-register → deploy json to host → cmk-agent-ctl import . gierse,. 1. Bulk Consent Manager. 1. Sehr beliebt ist z. mictlancihuatll. Use the cmk-agent-ctl register command to register. The exact command line is this: cmk-agent-ctl register -v -H HOSTNAME -P 'PASSWORD' -s SUBDOMAIN. socket (failed failed) so I stopped and disabled them, then did systemctl daemon-reload and systemctl. Hi everybody, i’am new to checkmk and trying to configure the agent but getting the same message, i couldn’t understand why. 0 2. Bei einem Netzwerkdienst liegt es nahe, den Dienst über das Netzwerk abzufragen und über diesen Weg auch zu überwachen. gerhards. So if you make any changes to the config file then you need to reload configuration or restart the agent. exe . 0. There were some user permission issues with the agent registration (cmk-agent-ctl register. 1. deb The monitored system is in a local network and have. INFO [cmk_agent_ctl::site_spec] Failed to discover agent receiver port using ERROR [cmk_agent_ctl] Failed to discover agent receiver port from Checkmk REST API, both with and Run with verbose output to see errors. service I see this error: ERROR [cmk_agent_ctl] Failed to listen on TCP socket for incoming pull connections. root@mgmonitor02:~# cmk-agent-ctl register --hostname MGMonitor --server localhost --site sitename --user omd --password omd ERROR [cmk_agent_ctl] Failed to discover agent receiver port from Checkmk REST API, both with and c3rberus (MD) December 17, 2021, 4:52am 3. Der Agent Controller cmk-agent-ctl kümmert sich um den Transport der vom Agentenskript gesammelten Daten. We strongly recommend to enable TLS by registering the host to the site (using the `cmk-agent-ctl register` command on the monitored host). So if you make any changes to the config file then you need to reload configuration or restart the agent. check_mk agent runs on top of xinetd service in Linux. If the host is monitored by multiple sites, you must register to. The registration against the corresponding slaves works fine and I can see with cmk-agent-ctl status, that the host is registered and in pull-mode now: image 843×285 37. 0 the new Linux agent with the Agent Controller supports the registered, TLS-encrypted and compressed pull mode. The Agent Controller cmk-agent-ctl is the component within the agent that is responsible for transporting the data collected by the agent script. Agent pairing; Read access to all hosts and folders Since Checkmk version 2. eu --site monitoring ^. I accept the certificate. 0p2 RAW Edition. You can learn how to use the agent here. The cmk-agent user was sucessfully created. The new TLS feature is need to register with cmk-agent-ctl register command. 7 LTS Attempting to register windows host with TLS upon performing corresponding command cmk-agent-ctl. So now you must de-register, on the host: cmk-agent-ctl delete-all --enable-insecure-connections Then on the CMK server: Properties of host, then menu entry Host > Remove TLS registration Afterwards connections should work albeit insecure. service should work as expected. I created the folder manually and changed ownership, and now the registration. But if cmk-agent-ctl cannot be started, access fails. 1 does not exist. net -i STAR -P 'XXXXX' -U automation -H sys-vbr02Yes I did use the” cmk-agent-ctl register command, after that I got this message. 0. Dazu verwendet Checkmk teils eigene, teils bereits existierende Plugins. But if cmk-agent-ctl cannot be started, access fails. There were some user permission issues with the agent registration (cmk-agent-ctl register. socket systemctl status cmk-agent-ctl-daemon. 0p10 OS: linux The hosts agent supports TLS, but it is not being used. Nun hast Du 2 Möglichkeiten: Entweder den controller für TLS registrieren (cmk-agent-ctl register -h für die Hilfe) oderCheckmk Enterprise Edition 2. So if you make any changes to the config file then you need to reload configuration or restart the agent. Checkmk Enterprise Edition 2. cfg. socket (failed failed) so I stopped and disabled them, then did systemctl daemon-reload and systemctl. The cmk-agent user is created during the installation of the agent. If I try to register it with the command: cmk-agent-ctl register --detect-proxy --hostname FOO --server bla. 0 then you will find the systemd unit files inside. The registration then aborts, since we cannot continue without knowing the correct port. scheint mir noch nicht ganz ausgereift. If the host is monitored by multiple sites, you must register to all of them. 1. com:8000 --site itbetrieb --user automation --password xxxxxxxx --trust-cert -vv Version: 2. g. 1 gave 404 Not Found: Host 127. Agent pairing; Read access to all hosts and folders; Write access to all hosts and folders; regards. WalterH (Walter Hofstädtler) May 30, 2022, 5:42pm 31. So now you must de-register, on the host: cmk-agent-ctl delete-all --enable-insecure-connections Then on the CMK server: Properties of host, then menu entry Host > Remove TLS registration Afterwards connections should work albeit insecure. Hello. p3 OS version: CentOS 8. 1. net -i STAR -P 'XXXXX' -U automation -H sys-vbr02Apparently I’m too stupid to find the correct call for agent registration via REST API in any documentation. The exact command line is this: cmk-agent-ctl register -v -H HOSTNAME -P 'PASSWORD' -s SUBDOMAIN. 2. socket systemctl status cmk-agent-ctl-daemon. 0 adds the Agent Controller and new features to the agent script. exe' register -s checkmk. The additional port 8000 seems necessary for creating TLS connection. Back on server, Add server under hosts. 0:8282 --site cmk --user automation --password. 0 adds the Agent Controller and new features to the agent program. 0p9. Without register, the communication will handle also via port 8000, so you need to clarify if this port is open. Reloading xinetd Activating systemd unit 'check-mk-agent. After a reboot the cmk-agent-ctl-daemon and the check-mk-agent. The cmk-agent user is created during the installation of the agent. But if cmk-agent-ctl cannot be started, access fails. deb. service: Scheduled restart job, restart counter is at 2. exe” register. Could you please check who is claiming port 6556? ss -tulpn | grep 6556 This should be cmk-agent-ctl in daemon mode. Then I installed the agent on the server, and registered, and this part finally worked, the server can monitor itself (even if I don’t understand why cmk-agent-ctl register --hostname 127. 0-1_all. exe' register -s checkmk. To register a host, users need the following permissions: Agent pairing. Any hints? aeckstein (Andre Eckstein) October 25, 2022, 4:36pm 4. 2 system. Er wird unter dem Benutzer cmk-agent ausgeführt, der nur beschränkte Rechte besitzt, z. 1. If you use the bakery, the agent was baked with enabled cmk-agent-ctl. I dont know why this folder could not be created during cmk agent installation from the cmk-agent-useradd. The exact command line is this: cmk-agent-ctl register -v -H HOSTNAME -P 'PASSWORD' -s SUBDOMAIN. socket. exe register --hostname xxx --server checkmk:8000 --site monitoring --user automation --password xxx That seemed to have worked great thanks “jwiederh”. The agent controller is well deployed and configured : “C:Program Files (x86)checkmkservicecmk-agent-ctl. py page via wget when I supply the correct credentials. 1. 0/26. Upon first try, “cmk-agent-ctl register. As suggested in another post i read i checked:-that port 8000 is open-omd config show | grep AGENT_RECEIVER show port 8000cmk-agent-ctl register --server cmkserver:443 --trust-cert --site cmksite --user username --password password --hostname monitoringhost On Debian 11 if got the following outputCMK version: 2. 1. This might be a bug. exe” ^. serviceThis is a bug of the client cmk-agent-ctl. This might be a bug. 1. 0p12. In your case. Output of “cmk --debug -vvn hostname”: (If it is a problem with checks or plugins) I have registered over 100 hosts successfull but something is wrong with this one when I use that command: & 'C:Program Files (x86)checkmkservicecmk-agent-ctl. Welcome to the Checkmk User Guide. ourcompany. OK, let’s figure out who is doing what. rs:14: starting [2023-02-10 12:54:18. Here you can enter a host’s name simply in order to view the host’s configuration (e. rs:14: st… As mentioned in another thread, you actually ran into a newly implemented CSR version check that’s. 0p12 Agent socket: operational IP allowlist: any Connection: xxxxx UUID: xxxxxx Local: Connection type: pull-agent Certificate issuer: Site 'xxx' local CA Certificate validity: Wed, 05 Oct 2022 12:04:40 +0000 - Mon, 05 Feb 3021 12:04:40 +0000 Remote: Connection type: pull-agent. Currently, only systemd on the x86_64 platform is. exe register --trust-cert -vv” command: [2023-02-10 12:54:18. cmk-update-agent register -v -H COMPUTERNAME -U register -S xxxxxxxxxxxxxxxxx. 0p20 Debian 11. I’m using CMK 2. If it is not that, double-check your TLS registration process per our official guide: Monitoring Linux - The new agent for Linux in detail. 0p14 Agent socket: operational IP allowlist: 10. I tried the following: apt purge check-mk-agent; manually removed some leftovers rm -r /var/lib/cmk-agent rm -r /var/lib/check_mk_agent; systemctl | grep check still showed two services, system-check_mk. I dont know why this folder could not be created during cmk agent installation from the cmk-agent-useradd. local -i home -U cmkadmin ERROR [cmk_agent_ctl] Failed to discover agent receiver port from Checkmk REST API, both with and Registration indeed is good. It has to be a check_mk user, try with cmkadmin. This can be problematic if you are monitoring the same host from a site running Checkmk version 2. target. g. 1. mschlenker (Mattias. Bei der Registrierung der Agents ergibt sich bei beiden Server folgender Fehler: <HOST>:~ # cmk-agent-ctl register --hostname <HOSTNAME> --server 192. 1. apt remove --purge check-mk-agent dpkg -i check-mk-agent_2. After the installation everything worked. service. 488899 +01:00] INFO [cmk_agent_ctl] srcmain. Deutsch. socket systemctl status cmk-agent-ctl-daemon. If I try to register it with the command: cmk-agent-ctl register --detect-proxy --hostname FOO --server bla. You already entered the right command with openssl s_client -connect SLAVE01:443. 0. local:8000 -s checkmk. 1. With telnet i can connect to the agent from the OMD server. 1 Like. service should work as expected. Anyhow when registering the usual way as I did it. You can display command help with cmk-agent-ctl help, also for specific available subcommands, with cmk-agent-ctl help register for example. Attempting to register at checkmk. 0p10 Agent socket: operational IP allowlist: any Connection: localhost:8001/cmk UUID: 186f71b9-8d6f-41c6-be44-bb1f7c23ae7b Local: Connection. Did not fix it. The controller is executed under the cmk-agent user, which has limited privileges, e. The hostname “localhost” was wrong. Das zu bestätigende Server-Zertifikat haben wir aus Gründen der. local --server 10. As suggested in another post i read i checked:-that port 8000 is open-omd config show | grep AGENT_RECEIVER show port 8000It seams you use a Debian system. In any of these cases I can replace localhost with the actual hostname as well and the results don’t change (they’re identical). If the Agent Receiver accepts the request, registration is performed and a TLS-encrypted connection is established. Create MSI file for windows 2019 server. The controller is executed under the cmk-agent user, which has limited privileges, e. OS version: TrueNAS SCALE 22. I am trying to register an agent installed on a Windows Server 2019. service. service1. 1. Please provide me with the output of: systemctl status check-mk-agent. Dann hast du die Herangehensweise schon gefunden, wenn man die Zertifikate noch nicht im Griff hat. In your case. trying to register a client is not possible because the cmk controller is looking for a socket (systemd) [root@jumphost]# cmk-agent-ctl status Version: 2. We strongly recommend to enable TLS by registering the host to the site (using the `cmk-agent-ctl register`. 1. On a related note, I’ve been following the beginner’s guide on setting up Checkmk and found that registering the Checkmk Agent for monitoring the monitoring server itself not working. 1. 5. socket (failed failed) so I stopped and disabled them, then did systemctl daemon-reload and systemctl. exe" ^ register ^ --hostname mynewhost ^ -. Hello. To register the agent, I ran: sudo cmk-agent-ctl register --hostname localhost --server localhost:8001 --site cmk --user cmkadmin That gives: > sudo cmk-agent-ctl status Version: 2. service: Scheduled restart job, restart counter is at 2. Output of “cmk --debug -vvn hostname”: (If it is a problem with checks or plugins) sudo: cmk: command not found. exe to register the Agent Controller. 1. I installed the CheckMK Agent on a TrueNAS SCALE host. Agent Controller is not running, no config files can be found in the systemd directory and within xinetd. $ cmk-update-agent register $ cmk-agent-ctl register. cmk-agent-ctl register -v -H HOSTNAME -P 'PASSWORD' -s SUBDOMAIN. mschlenker (Mattias Schlenker) July 8, 2022, 8:12am 4. cmk-agent-ctl register --hostname localhost --server server:8000 --site mysite --user cmkadmin -vv. So now you must de-register, on the host: cmk-agent-ctl delete-all --enable-insecure-connections Then on the CMK server: Properties of host, then menu entry Host > Remove TLS registration Afterwards connections should work albeit insecure. evilguy January 8, 2023, 7:53pm 3. For Debian remove the cmk-agent and purge the configuration, than reinstall the agent, this purges the xinetd configuration. This might be a bug. It has to match the actual hostname used by the Checkmk server, found under “Setup” > “Hosts”. If it is xinetd remove the. For Debian remove the cmk-agent and purge the configuration, than reinstall the agent, this purges the xinetd configuration. Dazu verwendet Checkmk teils eigene, teils bereits existierende Plugins. I dont know why this folder could not be created during cmk agent installation from the cmk-agent-useradd. 0p10 Agent socket: operational IP allowlist: any Connection: localhost:8001/cmk UUID: 186f71b9-8d6f-41c6-be44-bb1f7c23ae7b Local: Connection. C:ProgramDatacheckmkagentconfigcasall_certs. Hello. Hi, Some days ago i was testing this software, do a few tests and lately installed on a VM runing linux mint 20. Checkmk Appliance Cluster. no login shell, and is used only for data transfer. 5. 0p20 Debian 11. 0p27 OS version: Ubuntu 20. You can display command help with cmk-agent-ctl help, also for specific available subcommands, with cmk-agent-ctl help register for example. I am experiencing a problem with registering the agent: CMK version: 2. service should work as expected. I am not able to debug the cmk-agent-ctl since it is in binary form: You can display command help with cmk-agent-ctl help, also for specific available subcommands, with cmk-agent-ctl help register for example. 0. This one is listening at port 8000. mschlenker (Mattias Schlenker) July 8, 2022, 8:12am 4. g. The client must set the version 0 for the CSRThe register command cmk-agent-ctl register often gets confused with the Agent update registration cmk-agent-update register, but these are two different registration types: one for TLS encryption and one for registering automatic updates (Agent Bakery, cee). 0p20 Ubuntu 20. I have around 60 Windows servers which I have checked using a backed agent. 1 i’m trying to automate the process of registering our updated windows hosts to thee monitoring for tls encryption. We strongly recommend to enable TLS by registering the host to the site (using the `cmk-agent-ctl register` command on the monitored host). service: Start request repeated too quickly. 0p6. exe' register -s checkmk. In your case doing proxy. socket'. Sie können sich mit. systemctl stop cmk-agent-ctl-daemon. serviceCan you use the option trust-cert ? Also, what is the systemd version on your system ?So now you must de-register, on the host: cmk-agent-ctl delete-all --enable-insecure-connections Then on the CMK server: Properties of host, then menu entry Host > Remove TLS registration Afterwards connections should work albeit insecure. Checkmk Community Trouble after upgrading to 2. The controller is executed under the cmk-agent user, which has limited privileges, e. echo y|sudo cmk-agent-ctl register --hostname vmansible01 –server vmcheckmk01. I created the folder manually and changed ownership, and now the registration is working! ERROR [cmk_agent_ctl] Something seems wrong with the agent socket (/run/check-mk-agent. socket systemctl disable cmk-agent-ctl-daemon. I am trying to register an agent installed on a Windows Server 2019. CMK 2. The cmk-agent user was sucessfully created. consorzioburana. 514. What I already tried: I tried only listening on ports 80 and 443 for caddy, with {"serverDuration": 24, "requestCorrelationId": "464b55cee9f74460a402ac4a40d2b489"} Checkmk Knowledge Base {"serverDuration": 18, "requestCorrelationId. The controller is executed under the cmk-agent user, which has limited privileges, e. 1 Like. 4. I am trying to register an agent installed on a Windows Server 2019. mschlenker (Mattias Schlenker) May 30, 2022, 6:11pm 4. 6. I had to add the checkmk user again. I am using the Raw edition of CheckMK for my (rather large) Hobbyist stuff. 0. Now you need to register the agnet for TLS handshake. Release notes. But if cmk-agent-ctl cannot be started, access fails. The cmk-agent user was sucessfully created. Whether the host is configured for the pull mode (all editions) or the push mode (only the Cloud Edition) makes no difference for the command examples. 0p15 OS version: TrueNAS SCALE 22. 1 the monitoring data sent from the monitored host to the monitoring server is TLS encrypted and compressed by default. omd update. When I try to register the agent on the host system with: cmk-agent-ctl register --hostname some_hostname --server 127. The controller is executed under the cmk-agent user, which has limited privileges, e. exe . net -i STAR -P 'XXXXX' -U automation -H sys-vbr02Registration indeed is good. service: Scheduled restart job, restart counter is at 2. service systemctl disable cmk-agent-ctl-daemon. I am trying to add new servers with: amnesiac ≫ [ 10:47:25 ] ≫ ~ $ cmk-agent-ctl register-new --server. Rg, ChristianThe Agent Controller cmk-agent-ctl is the component within the agent that is responsible for transporting the data collected by the agent script. exe" register --hostname s3mo-tape. : checkmk:~# systemctl status cmk-agent-ctl-daemon. $ sudo systemctl restart cmk-agent-ctl-daemon. exe – register --trust-cert’ USAGE: cmk-agent-ctl. The hosts agent supports TLS, but it is not being used. exe register --trust-cert -vv” command: [2023-02-10 12:54:18. I want to enable global registration via Hostname for other agents too, so I’ve enabled a nginx-reverseproxy with following settings:Hi, I have a weird problem with 3 nodes (Ubuntu 20. After the installation everything worked. . You can display. Thx karnicmk-agent-ctl register -v -H HOSTNAME -P 'PASSWORD' -s SUBDOMAIN. apt remove --purge check-mk-agent dpkg -i check-mk-agent_2. TLD -i SITE-NAME -U USERNAME. mschlenker (Mattias Schlenker) May 30, 2022, 6:11pm 4. Thanks for your responses! @cyr0nk0r I rebaked the Agent using HTTP only and got rid of the. Wie hier beschrieben, sollten alle Bedingungen für eine TLS encryption erfüllt sein. Whether the host is configured for the pull mode (all editions) or the push mode (only the Cloud Edition) makes no difference for the command examples. I have the server up and running and ~50 VMs online, all is working well. The Windows agent. cmk-agent-ctl delete-all --enable-insecure-connections; cmk-agent-ctl status; cmk-agent-ctl register --hostname $(hostname -f) --server checkmk21-prod. However, the certificate rolled out by the agent updater ruleset seems to be insufficient. The agent-receiver of the first checkmk instance usually listens on port 8000, this is the port you need the agent to register against. However if I (faulty) try to register the host to my MAIN site first and THEN register to my slave site it works… The --hostname option of the register command refers to the host to be registered. domain. In checkmk for the host service got below warning. You can display command help with cmk-agent-ctl help, also for specific available subcommands, with cmk-agent-ctl help register for example. Copy the cmk-update-agent binary or the cmk_update_agent. I want to enable global registration via Hostname for other agents too, so I’ve enabled a nginx-reverseproxy with following settings:Yes I did use the” cmk-agent-ctl register command, after that I got this message. DOMAIN. I am trying to register an agent installed on a Windows Server 2019. , I had to put the public hostname). service You can display command help with cmk-agent-ctl help, also for specific available subcommands, with cmk-agent-ctl help register for example. mschlenker (Mattias Schlenker) July 8, 2022, 8:12am 4. XXX. We’ll come back to you to ask for. no login shell, and is used only for data transfer. Our Manufacturers. 0p20 Debian 11 Hi everyone, below is the output of the “cmk-agent-ctl. Sehr beliebt ist z. in the host run the register checkmk agent. 5 LTS I have had no issues registering the agent on internal servers, but I have two servers hosted in the cloud which are fully connected and have appropriate NAT rules and local firewall rules to allow the communication, but registering results in the error: ERROR [cmk_agent_ctl] Operation. Since the machine you’re trying to monitor is still 2. error: The subcommand ‘register --trust-cert’ wasn’t recognized Did you mean ‘register’? If you believe you received this message in error, try re-running with ‘cmk-agent-ctl. The Agent Controller cmk-agent-ctl is the component within the agent that is responsible for transporting the data collected by the agent script. 1. So now you must de-register, on the host: cmk-agent-ctl delete-all --enable-insecure-connections Then on the CMK server: Properties of host, then menu entry Host > Remove TLS registration Afterwards connections should work albeit insecure. The port can either be included in the server name argument ( -s ), or it can be left out.