Boundary Desktop - Client Agent not starting reliably (localhost:9300 connection refused)

Boundary
1

Hello,

I’m using Boundary Desktop on Windows 10, and I’m experiencing intermittent issues where the client agent fails to start properly.

Sometimes, I’m able to connect to SSH targets without any problem. Other times, launching a session fails with this repeating error in the logs:

Client Agent Status: client do failed: GET http://localhost:9300/v1/status: connectex: No connection could be made because the target machine actively refused it.

What’s confusing is that this behavior is not consistent — the same target might work at one moment and fail later, without any change in configuration.

Here’s what I’ve already tried:

  • Reinstalled the latest version of Boundary Desktop
  • Deleted AppData\Roaming\Boundary Desktop and ~\.boundary\socket\daemon.sock
  • Launched the app as Administrator
  • Confirmed that no process is using port 9300 (netstat -ano)
  • Checked the logs in AppData\Roaming\Boundary Desktop\logs, but found no crash info related to the agent

Also, there’s no network issue between my machine and the SSH targets — they’re all located in the same VLAN, and direct SSH works fine using ssh from the terminal.

I’m able to authenticate, browse targets, and see available sessions — but the ones that require the local agent (like SSH via Desktop) randomly fail depending on whether the client agent manages to start.

Is there any way to force the agent to launch, or debug why it silently fails to bind on localhost:9300?

Thanks for your help!

2

Could you please share the Client Agent log file so we can investigate the issue further?

Additionally, please check if there are any conflicting software running on the machine that might interfere with the Client Agent.

3

Thanks for getting back to me.

Here are the latest logs from my Boundary Desktop Client. I’m still seeing the same recurring client agent error:

[2025-04-10T09:07:26.894+02:00] [warn]  Client Agent Status: {"error":"clientagentcmd.(StatusCommand).Status: client do failed: unknown: error #0: GET http://localhost:9300/v1/status giving up after 2 attempt(s): Get \"http://localhost:9300/v1/status\": dial tcp [::1]:9300: connectex: No connection could be made because the target machine actively refused it."}

And just a few minutes later:

[2025-04-10T09:13:19.790+02:00] [warn]  Client Agent Status: {"error":"clientagentcmd.(StatusCommand).Status: client do failed: unknown: error #0: GET http://localhost:9300/v1/status\": dial tcp [::1]:9300: connectex: No connection could be made because the target machine actively refused it."}

At the same time, search requests and resource loading appear to work normally:

[2025-04-10T09:13:12.131+02:00] [debug] Search request took 266 ms {
  force_refresh: true,
  query: '(id = "ttcp_4JLJqDpt7z" or id = "ttcp_VSHuva5f"...)',
  resource: 'targets'
}
[2025-04-10T09:13:16.405+02:00] [debug] Search request took 272 ms {
  query: '(user_id = "u_KcXTYIXIqX") and (status = "active" or "pending")',
  resource: 'sessions'
}

Also, when trying to connect to an SSH target, I sometimes get this:

kex_exchange_identification: read: Connection reset

However, I can often still connect to my targets even when these errors show up, which is strange. I’m not sure if the agent is briefly starting, or if some sessions are handled without it.

4

Hi Reyan,

Thanks for sharing those details.

Just to clarify—I’m specifically requesting the Client Agent logs, not the Boundary Desktop Client logs. The file I’m looking for should be located at:

C:\Windows\Logs\boundary-client-agent.log

Could you please upload that file so we can investigate the client agent issue more thoroughly?

Also, I wanted to follow up on my earlier question—can you please check if there’s any conflicting software running on the machine that might interfere with the Client Agent?

Appreciate your help!

5

Thanks for the clarification.

Just to let you know — I’m currently using the Community version of Boundary, and the file path
C:\Windows\Logs\boundary-client-agent.log does not exist on my system.

I’ve checked the entire C:\Windows\Logs directory and couldn’t find any file or folder related to the Boundary client agent.

Please let me know if the Community version stores these logs in a different location, or if there’s a way to enable verbose logging for the agent.

6

Can you please share the commands you’re using to connect to SSH targets.

Please note that Boundary Client Agent is an enterprise feature, which requires HCP Boundary or Boundary Enterprise.

7

Okay, I found the solution. I had a communication issue because TLS was enabled on one worker and not on the others. Thank you for your help !