Cray System Management Documentation > Cray System Management (CSM) Administration Guide > node management > Enable Passwordless Connections to Liquid Cooled Node BMCs

Enable Passwordless Connections to Liquid Cooled Node BMCs

Set the passwordless SSH keys for the root account and/or console of all liquid-cooled Baseboard Management Controllers (BMCs) on the system. This procedure will not work on BMCs for air-cooled hardware.

Warning: If administrator uses SCSD to update the SSHConsoleKey value outside of ConMan, it will disrupt the ConMan connection to the console and collection of console logs. Refer to ConMan for more information.

Setting up SSH keys enables administrators to view recent console messages and interact with the console device for nodes.

Prerequisites

The Cray command line interface (CLI) tool is initialized and configured on the system. See Configure the Cray CLI.
This procedure requires administrative privileges.

Procedure

Save the public SSH key for the root user.

ncn-w001# export SSH_PUBLIC_KEY=$(cat /root/.ssh/id_rsa.pub | sed 's/[[:space:]]*$//')

Enable passwordless SSH to the root user of the BMCs.

Skip this step if passwordless SSH to the root user is not desired.
```
ncn-w001# export SCSD_SSH_KEY=$SSH_PUBLIC_KEY
```
Enable passwordless SSH to the consoles on the BMCs.

Skip this step if passwordless SSH to the consoles is not desired.
```
ncn-w001# export SCSD_SSH_CONSOLE_KEY=$SSH_PUBLIC_KEY
```

Generate a System Configuration Service configuration using the scsd tool.

The administrator must be authenticated to the Cray CLI before proceeding.

ncn-w001# cat > scsd_cfg.json <<DATA
{
   "Force":false,
   "Targets":
$(cray hsm state components list --class mountain --type nodebmc --format json | jq '[.Components[] | select((.State == "On") or (.State == "Ready")) | .ID]')
   "Params":{
      "SSHKey":"$(echo $SCSD_SSH_KEY)",
      "SSHConsoleKey":"$(echo $SCSD_SSH_CONSOLE_KEY)"
   }
}
DATA

Inspect the generated scsd_cfg.json file.

Ensure that the following are true before running the command below:
- The component name (xname) list looks valid/appropriate.
- The SSHKey and SSHConsoleKey settings match the desired public key.
Load the configuration from the file to the System Configuration Service.
```
ncn-w001# cray scsd bmc loadcfg create scsd_cfg.json
```
Check the output to verify all hardware has been set with the correct keys. Passwordless SSH to the root user and/or the consoles should now function as expected.