Cisco Umbrella is a leading DNS-layer security solution designed to protect businesses from cyber threats such as malware, phishing, and data exfiltration. By managing DNS traffic, Cisco Umbrella enforces security policies that ensure safe internet usage across networks. However, there are situations where it may become necessary to bypass Cisco Umbrella temporarily, such as during DNS troubleshooting or when addressing compatibility issues with certain applications.
This guide explains how to bypass Cisco Umbrella safely and highlights important considerations to minimize security risks. Whether you are managing a Microsoft DNS server or a BIND server, this article offers actionable steps for bypassing Cisco Umbrella in specific scenarios. For expert assistance with DNS configurations or Cisco products, contact Stratus Informational Systems today.
Why Bypassing Cisco Umbrella May Be Necessary
While Cisco Umbrella is a robust security solution, there are scenarios where bypassing it may be necessary. It is crucial to understand these situations and proceed with caution, as bypassing DNS-layer protection can expose your network to risks.
Common Reasons for Bypassing Cisco Umbrella
- Troubleshooting DNS Issues: When DNS queries fail due to Geo-IP filtering, rate limiting, or DNSSEC validation problems.
- Compatibility Problems: Some legacy systems or custom applications may not function properly with DNS-layer filtering enabled.
- Specific Domain Requirements: Certain DNS records may require alternative handling that Cisco Umbrella cannot accommodate.
Potential Risks of Bypassing Cisco Umbrella
Bypassing Cisco Umbrella disables a critical layer of security, increasing vulnerability to malicious sites, phishing attacks, and other cyber threats. It is important to implement bypasses only as a temporary measure and ensure logs are maintained to monitor potential risks.
Professional Support for DNS Troubleshooting
For organizations facing complex DNS issues, consulting dedicated professionals is essential. Stratus Informational Systems provides tailored DNS solutions and expert guidance to ensure security and functionality remain intact.
A Step-By-Step Guide
Conditional forwarding is a method used for Cisco Umbrella bypass for specific domains. This approach is particularly useful for businesses that need to route DNS queries for certain zones through alternative DNS servers.
3.1 Conditional Forwarding on Microsoft DNS Server
What is Conditional Forwarding?
Conditional forwarders allow DNS servers to forward queries for specific domains to alternative DNS servers. This ensures only the necessary DNS traffic bypasses Cisco Umbrella while retaining security policies for the rest of the network.
Steps to Configure Conditional Forwarding
- Access the DNS Manager:
- Open the DNS Manager on your Windows server.
- Create a New Conditional Forwarder:
- Right-click on “Conditional Forwarders” and select “New Conditional Forwarder.”
- Specify the Domain to Bypass:
- Enter the domain name (e.g., problemzone.tld) that requires a bypass.
- Set Forwarding Servers:
- Enter the IP address of the alternative DNS server that will handle queries for the specified domain.
- Validate the Configuration:
- Test the configuration to ensure that queries for the specified domain resolve correctly.
Best Practices
- Document all changes to the DNS configuration.
- Limit bypasses to specific domains to minimize security risks.
For further assistance with DNS configurations, consult Stratus Informational Systems for professional support.
3.2 Conditional Forwarding on BIND Server
Understanding BIND and Forwarding
BIND is a widely used DNS server that supports conditional forwarding through its configuration file. By editing the named.conf file, administrators can define forwarders for specific domains.
Steps to Configure Conditional Forwarding in BIND
- Edit the Configuration File:
- Open the named.conf file in a text editor.
- Define the Zone:
zone “problemzone.tld” {
type forward;
forwarders { 8.8.8.8; }; // Example alternative DNS server
};
- Save and Validate:
- Save the configuration and run named-checkconf to verify its correctness.
- Restart the DNS Service:
- Restart BIND to apply the changes.
A business application hosted on a specific domain may require direct access to an external DNS server. Using conditional forwarding in BIND ensures the necessary bypass without affecting other DNS traffic.
Umbrella-Specific Considerations
Internal Domains Feature
Cisco Umbrella allows administrators to configure bypasses directly through its dashboard using the “Internal Domains” feature. This ensures that certain domains bypass Umbrella’s policies while maintaining centralized control.
Network Device Integrations
For organizations using Cisco network devices, such as ASA firewalls or ISR routers, Umbrella policies can be customized to enable domain-specific bypasses. This provides flexibility for handling complex DNS requirements without compromising overall security.
Roaming Clients
Roaming clients can also be configured to bypass specific domains by modifying their local DNS settings or through Umbrella’s policy configurations. This is particularly useful for remote workers accessing corporate applications.
Risks and Best Practices When Performing a Cisco Umbrella Bypass
Security Risks
Bypassing Cisco Umbrella exposes networks to increased risks, including:
- Access to malicious sites.
- Reduced visibility into DNS traffic.
- Potential data breaches.
Best Practices
- Restrict Bypasses: Limit bypasses to specific domains and timeframes.
- Monitor Logs: Track DNS queries to ensure bypassed domains are not abused.
- Consult Experts: Work with professionals to minimize risks and implement secure configurations.
Alternatives to Full Bypasses
Instead of bypassing Cisco Umbrella entirely, consider adjusting policies or using split tunneling to balance security and functionality. Stratus Informational Systems offers customized solutions to address these challenges effectively.
Conclusion
Cisco Umbrella provides essential DNS-layer protection for businesses, but certain scenarios may require temporary bypasses. By using methods like conditional forwarding and leveraging Umbrella’s flexible features, administrators can address specific requirements without compromising security.
For tailored guidance and professional DNS configuration support, contact Stratus Informational Systems today. Our team specializes in Cisco Umbrella and other DNS solutions to keep your business secure and efficient.
