PuTTY Connection Timeout: Understanding and Fixing It
PuTTY is a widely used SSH client, but users often encounter connection timeouts, leading to frustration. This issue typically arises when there's no activity within a specified timeframe, causing the server to terminate the connection. Fortunately, there are several ways to prevent these timeouts and ensure a stable connection.
Identifying the Root Cause
Before implementing any fix, it's essential to understand why the timeout is occurring. Common causes include:
- Server-side Configuration: The server may have a low inactivity timeout configured.
- Network Issues: Intermittent network connectivity can trigger timeouts.
- Firewall Restrictions: Firewalls might be dropping idle connections.
- PuTTY's Default Settings: PuTTY's default configuration might not be optimized for long-lived connections.
Implementing the Keep-Alive Solution in PuTTY
The most effective solution is configuring PuTTY to send null packets at regular intervals, effectively "keeping the connection alive." Here's how:
- Open PuTTY Configuration: Launch PuTTY and load your saved session or create a new one.
- Navigate to Connection Settings: In the left-hand panel, go to Connection.
- Set the "Seconds between keepalives": Locate the "Sending of null packets to keep session active" section. Enter a value, typically between 30 and 60 seconds. Setting it to 60 means PuTTY will send a null packet every minute.
- Save the Configuration: Return to the "Session" category, select your saved session, and click "Save." This ensures the setting is applied for future connections.
- Test the Connection: Reconnect to your server and monitor the connection. You should no longer experience timeouts.
Important Considerations: While keep-alive packets prevent timeouts, excessively frequent packets can consume bandwidth and potentially trigger security alerts. A value between 30 and 60 seconds is generally a safe and effective compromise. If the issue persists, investigate server-side configurations or network issues.