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SSH : The negotiation of host key verification algorithm is failed



Hi, I have tried to install a SSH Load Average sensor for a Linuxserver and I get this errormessage: "The negotiation of host key verification algorithm is failed". When I try to connect with putty, the ssh-connection works. Can you say me what is going wrong?

key sensor ssh

Created on Oct 5, 2010 11:55:57 AM

1 Reply

Accepted Answer



Hello Jens,

I guess your SSHd-Service does not provide the needed cipher to get the PRTG-SSH-Sensor started properly. To determine what cipher is missed, take a look at the dmesg-output on the monitored system while the PRTG-SSH-Sensor tries to connect:

  1. On the Linux-console you should use the dmesg-command e.g. "dmesg|grep sshd" (further information with " man dmesg")
  2. Please search for lines similar to:
sshd[1914]: [ID 800047 auth.crit] fatal: Client and server could not agree on a common cipher: client "blowfish-cbc,cast128-cbc,aes128-cbc,3des-cbc", server "aes128-ctr,aes192-ctr,aes256-ctr,arcfour128,arcfour256,arcfour".

Created on Oct 5, 2010 2:56:56 PM by  Michael Zeidler [Paessler Support] (112) 3 1

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.