
Troubleshooting Agent Connection Issues
Outline
Diagnosis
The network is dropping the WebSocket connection every 60 seconds, which is preventing the agent from maintaining a stable connection to Polar Cloud.
Fix
1. Increase WebSocket/Idle Connection Timeout
Your firewall or network equipment is configured to close idle connections after 60 seconds. This needs to be increased to at least 5-10 minutes for WebSocket connections.
Where to check:
- Firewall settings: Look for "TCP timeout", "idle timeout", or "session timeout"
- Proxy server settings: WebSocket timeout or keep-alive settings
- Router/Gateway: Connection tracking timeout
Specific settings to change:
- Set WebSocket idle timeout to 300-600 seconds (5-10 minutes)
- Or disable timeout for connections to
*.polar3d.comor your Polar Cloud domain
2. Whitelist Polar Cloud WebSocket Traffic
Add these domains to your firewall/proxy allowlist with 'no timeout' or 'persistent connection' rules.
Domains to whitelist:
-
*.polar3d.com - Any specific Polar Cloud server domains you use
- WebSocket protocol (
wss://) specifically
Firewall rule example:
Source: Any
Destination: *.polar3d.com
Protocol: HTTPS/WSS (port 443)
Action: Allow
Session Timeout: Disabled or 600+ seconds
3. Disable SSL/TLS Inspection for Polar Cloud
If your network uses SSL inspection/deep packet inspection, it may be interfering with WebSocket connections. Add Polar Cloud domains to the SSL inspection bypass list.
Why: SSL inspection breaks WebSocket's persistent connection handshake.
4. Check for Proxy Server Interference
If you're using a proxy server (like Squid, Blue Coat, Zscaler, etc.), it needs to be configured to properly handle WebSocket connections.
Proxy settings needed:
- Enable WebSocket support
- Disable connection pooling for WebSocket connections
- Increase proxy timeout to 600+ seconds
- Add Polar Cloud to proxy bypass list (if possible)
5. Network Equipment to Check
Check these devices/systems:
Testing Steps:
- Test from a different network (home network, mobile hotspot): If it works here, it confirms it's your school/corporate network
- Temporarily disable firewall/proxy (if allowed): If it works, confirms firewall/proxy is the issue
- Check with IT department logs: Look for connection drops at ~60-second intervals, check for WebSocket connection denials or timeouts
- Work with IT to implement whitelisting: Provide them the Polar Cloud domain list, request WebSocket timeout increase to 600 seconds
Need to send an email to your IT department?
Subject: WebSocket Connection Timeout Issue - Need Firewall Configuration Update
Hi IT Team,
We're experiencing issues with our 3D printer management software (Polar Cloud Agent) that uses WebSocket connections to communicate with cloud servers. The connection is being dropped every 60 seconds, which is preventing normal operation.
Issue:
- WebSocket connection to
*.polar3d.comdisconnects every ~60 seconds - Connection successfully reconnects in 3-4 seconds
- Pattern repeats continuously, causing printer monitoring issues
Requested Fix:
- Increase WebSocket/idle connection timeout to 600 seconds (10 minutes) for connections to
*.polar3d.com - Whitelist
*.polar3d.comfor persistent WebSocket connections (port 443/HTTPS) - Disable SSL inspection/deep packet inspection for
*.polar3d.com(if applicable)
Technical Details:
- Protocol: WebSocket over TLS (wss://)
- Port: 443
- Domains:
*.polar3d.comand related Polar Cloud infrastructure - Current timeout: ~60 seconds (needs to be increased to 600+ seconds)
Test: The connection works fine on non-corporate networks (home/mobile), confirming this is a network policy issue.
Can you help adjust these firewall/proxy settings?
Thanks, [Name]
