Understand SWG Traffic Decryption with Enabled HTTPS Decryption

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Updated:October 27, 2025
Document ID:225303

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    Introduction

    This document describes how Cisco Secure Web Gateway (SWG) handles traffic decryption when HTTPS decryption is enabled.

    Prerequisites

    Requirements

    There are no specific requirements for this document.

    Components Used

    The information in this document is based on Cisco Secure Web Gateway.

    The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

    Problem

    In a web policy rule set  with HTTPS decryption enabled, traffic is decrypted only if a Server Name Indicator (SNI) is present in the TLS handshake.

    Solution

    Security and Acceptable Use Policies can still be applied based on the destination servers where the request is being sent to. Destination lists can be created for these destination servers and rules can be enforced accordingly.

    Any blocks for DNS policies for Tunnels and AnyConnect can still apply.

    Cause

    This behavior is by design.

    Revision History

    Revision Publish Date Comments
    1.0
    28-Oct-2025
    Initial Release
    TAC Authored

    Contributed by Cisco Engineers

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