QUIC (Quick UDP Internet Connections) is a transport layer protocol developed by Google to improve web performance and reduce latency. While QUIC offers speed benefits, it creates significant challenges for network security and reporting solutions like Cyfin. This article explains how QUIC works, its impact on your network visibility, and how to resolve issues associated with QUIC traffic.
QUIC is essentially HTTP/2 over UDP rather than the traditional TCP protocol. Where protocols like SPDY and HTTP/2 were incremental improvements to HTTP over TCP, QUIC takes a fundamentally different approach by using UDP as its transport mechanism.
The core issue is not with QUIC itself, but rather that most firewalls and security appliances do not recognize QUIC traffic as web traffic. This creates a significant security gap.
Traditional firewalls have extensive functionality for HTTP and HTTPS traffic:
These features work because firewalls can interpret HTTP/HTTPS traffic from Layer 4 up to Layer 7. However, QUIC uses UDP on ports 80 and 443 (the same ports as HTTP/HTTPS), but that’s where the similarity ends. Network devices cannot determine the application protocol and treat QUIC as generic Layer 4 UDP traffic.
When QUIC traffic bypasses inspection, organizations face:
Cyfin relies on comprehensive logging from your firewall or UTM to provide accurate web usage reports. When QUIC is enabled:
Normal HTTPS Traffic (Logged Properly):
QUIC Traffic (Limited Logging):
If you’ve noticed a recent decline in reported traffic to Google sites (YouTube, Gmail, Drive, etc.) in Cyfin, there is a high probability your firewall is allowing QUIC.
The good news is that when QUIC communication is blocked, browsers and servers automatically fall back to traditional HTTP/HTTPS over TCP, where traffic can be inspected, controlled, logged, and reported on normally.
Most firewall vendors recommend blocking QUIC until full protocol support is added to their products. Methods vary by firewall:
Important Consideration: Before blocking UDP on port 443, verify that you’re not blocking other legitimate services. Some applications like OpenVPN can use UDP on port 443 for SSL VPN connections.
Below are links and instructions for blocking QUIC on popular firewall platforms:
FortiGate firewalls offer multiple methods to block QUIC:
Method 1: Application Control (Recommended)
Method 2: Custom Firewall Policy
Note: From FortiOS v7.2.0 onward, the default QUIC blocking option was removed. You must now use Application and Filter Overrides to block QUIC.
Method 3: SSL Inspection Profile (FortiOS 7.4+)
Reference: Fortinet Community – Block QUIC Protocol
Palo Alto firewalls can inspect QUIC traffic but cannot decrypt it like traditional HTTPS. Blocking QUIC forces fallback to standard SSL/TLS which can be decrypted with SSL Forward Proxy.
Configuration Steps:
Note: With some Chrome versions, QUIC may be misidentified as “unknown-udp.” Create an additional rule to block unknown UDP traffic on ports 80 and 443.
Reference: Palo Alto Knowledge Base – Block QUIC
SonicWall offers multiple approaches depending on your firmware version:
Method 1: Application Control (SonicOS 6.x and later)
Method 2: Security Policy with Application Match (SonicOS 7.0+)
Method 3: Custom Firewall Service
References:
Sophos firewalls provide native QUIC blocking functionality:
Method 1: Firewall Rule with QUIC Blocking (Recommended)
Important: The “Block QUIC protocol” option only works when UDP 443/80 is included in the Services section of the firewall rule. If QUIC service is not included, the blocking will not function properly.
Method 2: Application Control
Method 3: Create Custom QUIC Service (if needed)
References:
Configuration Steps:
For Cisco Umbrella/AnyConnect SWG users, QUIC must be blocked to ensure proper proxy operation:
Reference: Cisco – Disable QUIC for AnyConnect SWG
Configuration Steps:
Configuration Steps:
If your specific firewall is not listed above, follow these general steps:
If firewall-level blocking isn’t possible, you can disable QUIC in browsers:
chrome://flags in the address barEnterprise Deployment via Group Policy:
edge://flags in the address barabout:config in the address barnetwork.http.http3.enabledfalseNote: Browser-level blocking requires configuration on every device and can be circumvented by users. Firewall-level blocking is the recommended enterprise solution.
Method 1: Chrome Developer Tools
If you see QUIC protocols, your browser is using QUIC and it’s likely not being blocked.
Method 2: Chrome QUIC Sessions
chrome://net-internals/#quic in the address barMethod 3: Browser Extension
After implementing firewall rules:
Google and other proponents claim QUIC reduces latency and improves page load times. However:
When deploying QUIC blocking:
Once QUIC is blocked and traffic falls back to standard HTTPS:
✓ Full deep packet inspection restored
✓ Malware scanning active on all web traffic
✓ Content filtering policies enforced
✓ Web usage policies properly applied
✓ Compliance requirements met
✓ Complete URL logging restored
✓ Accurate web category reporting
✓ Full user activity visibility
✓ Search term monitoring enabled
✓ YouTube video tracking operational
✓ Bandwidth reporting accuracy improved
✓ User productivity reports complete
Issue: Testing shows QUIC is still being used
Solutions:
Issue: Reports still don’t show full Google traffic details
Solutions:
Issue: Some applications stopped working after blocking UDP 443
Solutions:
QUIC is a modern protocol designed to make the web faster, but it creates significant security and reporting challenges. For organizations using Cyfin to monitor and report on web activity, QUIC represents a blind spot that can hide inappropriate usage, malware, and policy violations.
Key Takeaways:
Recommendation: Block QUIC protocol at your firewall until vendors provide full inspection capabilities. This ensures comprehensive security protection and complete visibility in your Cyfin reports.
Document Version: 1.0
Last Updated: November 2025
Applies To: Cyfin Web Reporting and all supported firewall platforms
SSL inspection (also known as TLS decryption or HTTPS interception) is a critical feature for Cyfin users, allowing deep analysis of encrypted employee web traffic to identify security threats, enforce policies, and generate comprehensive reports. Without proper SSL inspection, a significant portion of web activity remains hidden, creating blind spots that expose organizations to malware, data exfiltration, and compliance risks. However, enabling SSL inspection isn’t always straightforward. Issues like outdated certificates or enabled QUIC can disrupt functionality, leading to incomplete monitoring and undetected threats.
This knowledge base article outlines common pitfalls when setting up or maintaining SSL inspection, based on industry best practices and known challenges. It provides guidance to help Cyfin customers configure their environments effectively, whether they’re new to SSL inspection or troubleshooting existing setups. By addressing these issues, you can ensure Cyfin delivers full visibility into web traffic while minimizing disruptions.
Cyfin relies on decrypting SSL/TLS traffic to perform in-depth analysis, such as detecting malicious content, tracking user behavior, and generating accurate reports. Encrypted traffic now accounts for over 90% of web activity, making inspection essential for security. Without it, threats hidden in HTTPS streams— like command-and-control communications or phishing—go unnoticed, increasing the risk of breaches. Proper setup ensures Cyfin can inspect this traffic without compromising network performance or user experience.
Below are key issues that can hinder SSL inspection, along with symptoms, resolutions, and the security risks if left unaddressed. These are drawn from common network security challenges and apply to setups involving firewalls, proxies, or integrated tools like CyBlock (Wavecrest’s companion product for filtering).
Description: SSL inspection requires generating and using intermediate certificates signed by a trusted Certificate Authority (CA). Using expired, revoked, or mismatched certificates (e.g., those with SHA1 algorithms or improper chaining) can cause failures.
Symptoms: Connection errors, browser warnings (e.g., “NET::ERR_CERT_AUTHORITY_INVALID”), or incomplete decryption, leading to bypassed inspection.
How to Avoid:
Security Risks if Ignored: Partial or failed decryption leaves encrypted threats undetected, allowing malware or data leaks to bypass Cyfin’s analysis.
Description: QUIC (used in HTTP/3) is a UDP-based protocol with proprietary encryption that most inspection tools, including firewalls, cannot decrypt. It bypasses traditional SSL inspection over TCP.
Symptoms: Traffic to sites like Google or Facebook evades inspection, showing errors like “ERR_QUIC_PROTOCOL_ERROR” or incomplete Cyfin reports.
How to Avoid:
Security Risks if Ignored: QUIC traffic remains uninspected, hiding potential threats and reducing Cyfin’s effectiveness in monitoring employee activity.
Description: Client devices must trust the inspection device’s root CA certificate for seamless decryption. Without this, browsers and apps reject the intercepted certificates.
Symptoms: Persistent certificate warnings, blocked sites, or apps failing to connect (e.g., in managed environments).
How to Avoid:
Security Risks if Ignored: Users may disable inspection to avoid warnings, creating unmonitored traffic and exposing the network to risks Cyfin is designed to detect.
Description: Decrypting and re-encrypting traffic adds computational load, leading to latency, reduced throughput, and overburdened devices.
Symptoms: Slow network speeds, high CPU usage on firewalls/proxies, or dropped connections during peak times.
How to Avoid:
Security Risks if Ignored: Overloaded systems may fail to inspect all traffic, allowing threats to slip through undetected by Cyfin.
Description: Some apps/sites use certificate pinning, non-standard protocols, unsupported ciphers, or client certificate authentication, causing inspection to fail.
Symptoms: Specific sites (e.g., with HSTS or pinning) show errors, or apps like banking software refuse connections.
How to Avoid:
Security Risks if Ignored: Bypassed traffic remains unmonitored, potentially harboring malware or policy violations invisible to Cyfin.
Description: New features like DNS over HTTPS (DoH) or Encrypted Client Hello (ECH) obscure traffic metadata, reducing inspection effectiveness.
Symptoms: Incomplete visibility into traffic origins or content, leading to gaps in Cyfin reports.
How to Avoid:
Security Risks if Ignored: Evolving threats exploit these blind spots, evading Cyfin’s detection and increasing breach likelihood.
Description: Improper setup can expose sensitive data, violate privacy laws, or weaken security (e.g., using outdated TLS versions).
Symptoms: User complaints about privacy, legal challenges, or increased vulnerability to attacks.
How to Avoid:
Security Risks if Ignored: Beyond legal fines, misconfigurations can introduce new vulnerabilities, undermining Cyfin’s protective role.
By proactively addressing these pitfalls, Cyfin customers can achieve robust SSL inspection, maximizing security and visibility. If issues persist, contact Wavecrest support for tailored assistance.

In the digital era, as businesses rapidly shift towards cloud-based solutions and web applications, maintaining the security and integrity of data has become paramount. One such technique that stands out in ensuring a secure web environment is Secure Socket Layer (SSL) encryption. While SSL helps in securing the data in transit between the client and the server, it poses challenges for organizations when it comes to monitoring and reporting on employee web use. Here’s where SSL inspection comes into play.
When an organization does not employ SSL inspection, the encrypted nature of HTTPS connections makes it difficult to have a clear view of the online activities of its employees. In such cases, only the domain name is visible, leaving a blind spot in understanding the exact nature of the content accessed. For example, an employee could access a permitted domain but navigate to inappropriate or risky pages within that domain, all while going unnoticed.
With SSL inspection enabled, organizations can decrypt and view the content of HTTPS connections. This offers numerous advantages:
SSL inspection goes beyond just security; it’s about gaining clear visibility and understanding of employee web activity. This clarity ensures that the reports generated provide a true reflection of online behaviors, making them more accurate and informative. Without SSL inspection, organizations are merely scratching the surface, with a significant chunk of the web activity remaining concealed within the encrypted tunnel. In today’s cybersecurity landscape, where every bit of detail matters, SSL inspection emerges as a critical tool for ensuring both security and compliance.

In our ever-evolving digital landscape, the focus on cybersecurity and data integrity has never been higher. SSL inspection, which is the process of decrypting and inspecting HTTPS traffic to monitor and regulate web content, is one way organizations aim to boost their cybersecurity posture. Many businesses trust their firewalls to undertake this task, but as technology advances, this approach presents several challenges:
The computational load required to perform SSL inspection can be demanding, and this additional burden may affect a firewall’s core functions. If a firewall is overtaxed with decrypting and inspecting traffic, its primary responsibility—shielding your network from threats—may suffer.
Not all firewalls are created equal. While some might possess robust SSL inspection capabilities, others might offer limited functionality or none at all. If you’re relying on a firewall without the necessary capabilities, your organization’s web traffic remains largely unseen.
With encrypted DNS (DoH) and Encrypted Client Hello becoming increasingly popular, firewalls will find it increasingly challenging to intercept and examine traffic. These encryption advancements can limit the efficacy of even the most sophisticated firewalls, rendering them less effective for SSL inspection.
Given these challenges, many experts suggest looking beyond firewalls for SSL inspection.
For environments seeking comprehensive SSL inspection without overloading their firewall, proxy-based solutions are often the ideal answer. These solutions are specifically crafted to execute SSL inspection tasks, offering detailed monitoring and reporting on employee web activity.
One of the trusted names in this arena is Wavecrest Computing. With nearly three decades in the field, Wavecrest has designed tools like Cyfin and CyBlock to address the specific challenges of SSL inspection.
CyBlock stands out as a premium choice for those in need. Not only does it offer the extensive monitoring and reporting features found in Cyfin, but it can also filter web access in real-time if desired. For businesses solely seeking SSL inspection, monitoring, and reporting, CyBlock fits the bill perfectly.
Relying solely on a firewall for SSL inspection can lead to potential vulnerabilities and performance issues. As encrypted web traffic becomes the norm and emerging encryption technologies come into play, the challenges will only increase. Solutions like Cyfin and CyBlock from Wavecrest Computing can help businesses rise to these challenges, ensuring robust cybersecurity while providing detailed insights into web activity. If your current setup falls short or you’re aiming to optimize SSL inspection without taxing your firewall, Wavecrest offers the specialized solutions you need.
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