Extending SSH Session with Putty and ASA Firewall Configuration

As IT professionals, we often find ourselves working on complex network configurations, including firewalls and secure shell (SSH) connections. In this article, we will explore how to configure an SSH session timeout using Putty and ASA firewall settings.

Background

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When connecting to a Linux server via SSH using Putty, it's not uncommon to experience unexpected disconnections due to inactivity or login timeouts. This can be frustrating, especially when working on critical tasks that require uninterrupted access to the server. To mitigate this issue, we need to configure the SSH session timeout setting.

Configuring SSH Session Timeout with ASA Firewall

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To set the SSH session timeout using an ASA firewall, you'll need to navigate to the command reference documentation for your specific ASA model. Unfortunately, it appears that configuring a login timeout of 1 minute is not possible using the ASA's built-in configuration options. However, we can still achieve this by setting up an idle timeout and implementing additional measures.

Idle Timeout Configuration

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On an ASA, you can set the idle timeout for SSH connections using the following command:

`ssh timeout `

Replace `` with your desired timeout value in seconds. For example, to set an idle timeout of 1 minute, enter `ssh timeout 60`.

MPF Configuration

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Another option is to use Multi-Protocol Firewall (MPF) to configure the SSH session timeout. MPF allows you to specify custom timeouts for various protocols, including SSH. However, as mentioned earlier, the minimum available timeout value in MPF configuration examples is 5 minutes, which may not meet your requirements.

Putty Configuration

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To extend the SSH session using Putty, we can configure the terminal settings by editing the `.inputrc` file. This file controls various aspects of the terminal behavior, including key bindings and timeouts.

Open the `.inputrc` file in a text editor (create a new file if it doesn't exist) and add the following line:

`e 28':'`

This configuration setting will blank out the Enter key when Caffeine simulates it, preventing any accidental input during extended sessions.

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In this article, we have explored various methods for configuring an SSH session timeout using Putty and ASA firewall settings. While the ASA's built-in configuration options do not support a 1-minute login timeout, we can still achieve our goal by setting up an idle timeout and implementing additional measures such as MPF configuration or Putty terminal settings. By following these steps, you'll be able to extend your SSH session and minimize disruptions due to inactivity or login timeouts.

Putty ssh extend session