The proxy’s HTTP keep-alive timeout (set to 90s) is shorter than the agent’s WebSocket ping interval (120s). Idle connections are dropped by the proxy before the agent sends its next ping, triggering a broken pipe state.
Install pending security patches, specifically those related to default cipher suite priority (e.g., KB3042058 for older servers). 4. Analyze Installation Logs
The SentinelOne agent attempts to reuse TLS sessions for WebSocket connections to reduce latency. However, the corporate proxy (Palo Alto) enforces a maximum TLS session lifetime of 10 minutes, while the agent expects 60 minutes. After 10 minutes, the proxy closes the connection without proper FIN packet, causing the agent to interpret the next send attempt as a handshake failure → Error 2008 . sentinelone error code 2008
2008 Display Message: "Agent unable to establish real-time channel. WebSocket handshake failed. Check network and proxy settings." Observed Log Entry (from SentinelOneAgent.log ): [ERROR] [WebSocketManager] Code 2008: TLS handshake timeout after 30s. Endpoint ID: <UUID>, Console: [tenant].sentinelone.net, Proxy: proxy.corp.local:8080.
[Signature] Director, Security Operations April 14, 2026 The proxy’s HTTP keep-alive timeout (set to 90s)
: Confirm the token you are using is valid and copied correctly from the Management Console.
Execute SentinelCleaner.exe as an administrator to wipe all existing S1 artifacts. After 10 minutes, the proxy closes the connection
SentinelOneInstaller.exe -t YOUR_SITE_TOKEN_HERE