Description

[Description]

After restarting the gateway, nemoclaw connect command fails to establish SSH connection to the sandbox (handshake verification failed).

nemoclaw logs --follow

[1775117573.901] [gateway] [INFO ] [openshell_server::ssh_tunnel] SSH tunnel: connecting to sandbox
[1775117573.902] [gateway] [INFO ] [openshell_server::ssh_tunnel] SSH tunnel: TCP connected to sandbox
[1775117573.902] [gateway] [INFO ] [openshell_server::ssh_tunnel] SSH tunnel: sending NSSH1 handshake preface
[1775117573.902] [gateway] [INFO ] [openshell_server::ssh_tunnel] SSH tunnel: waiting for handshake response
[1775117573.902] [gateway] [INFO ] [openshell_server::ssh_tunnel] SSH tunnel: handshake response received
[1775117573.902] [sandbox] [INFO ] [openshell_sandbox::ssh] SSH connection: reading handshake preface peer=10.42.0.17:53800
[1775117573.902] [sandbox] [INFO ] [openshell_sandbox::ssh] SSH connection: preface received, verifying peer=10.42.0.17:53800 preface_len=155
[1775117573.902] [sandbox] [WARN ] [openshell_sandbox::ssh] SSH connection: handshake verification failed peer=10.42.0.17:53800

[Environment]

• Device: DGX Spark
• Node.js: v22.22.2
• npm: 10.9.7
• Docker: Docker Engine 29.1.3
• OpenShell CLI: 0.0.20
• NemoClaw: v0.0.3
• OpenClaw: 2026.3.11 (29dc654)

[Steps to Reproduce]

1. Complete NemoClaw onboarding with a sandbox.
2. Restart Gateway with the command: docker restart openshell-cluster-nemoclaw
3. Wait for the gateway container to be healthy, then run the nemoclaw connect command to connect to the sandbox.

[Expected Behavior]

  The sandbox can be connect succesfully.

[Actual Behavior]
The sandbox can't be connect with SSH handshake verification failed.

[NVB# 6041647]

[NVB#6041647]

[NVB#6076156]