SSH authentication issue : No suitable key exchange algorithm could be agreed. - Support and Troubleshooting

SSH authentication issue : No suitable key exchange algorithm could be agreed. Description SSH authentication or connection failure: No suitable key exchange algorithm could be agreed.

This message can be seen either during Discovery or Orchestration Activity and this could be due to MID server still using legacy SSH client J2SSH.

Resolution Enable the use of SNCSSH client for Discovery and Orchestration.

<table id="r_SSHDiscoveryParameters__table_hfq_ty2_xp" class="table frame-all" style="box-sizing: border-box; padding: 0px; margin: 0px; outline: 0px; border-spacing: 0px; border-collapse: collapse; background-color: #fafafa; width: 813px; border-left: 0px; border-right: 0px; max-width: 100%; border-bottom: 1px solid #dddddd; color: #343d47; font-family: Source_Sans_Pro, Gotham, Helvetica, Arial, sans-serif; font-size: 16px;"> Enable the ServiceNow SSH Client mid.ssh.use_snc Enables the ServiceNow SSH client (SNCSSH) on individual MID Servers. SNCSSH is a ServiceNow implementation of an SSH client and is active by default for all MID Servers on new instances, via a <a class="xref" style="box-sizing: border-box; padding: 0px; margin: 0px; outline: none; background-color: transparent; color: #d1232b; text-decoration-line: none; cursor: pointer;" title="Use properties to control the behavior of all probes on a MID Server or all probes on all MID Servers." href="https://docs.servicenow.com/csh?topicname=r_MIDServerProperties.html&version=latest#r_MIDServerProperties">MID Server property . Enabling the ServiceNow SSH client disables the legacy J2SSH client. Important: Mixing SSH client types for MID Servers connected to the same instance is not a good practice. Type: true | false Default value: false https://docs.servicenow.com/csh?topicname=r_MIDServerProperties.html&version=latest