• Skip to primary navigation
  • Skip to main content
  • Skip to footer

Cisco Umbrella

Enterprise network security

  • Contact Sales
  • Login
    • Umbrella Login
    • Cloudlock Login
  • Why Us
    • Why Cisco Umbrella
      • Why Try Umbrella
      • Why DNS Security
      • Why Umbrella SASE
      • Our Customers
      • Customer Stories
      • Why Cisco Secure
    • Fast Reliable Cloud
      • Global Cloud Architecture
      • Cloud Network Status
      • Global Cloud Network Activity
    • Unmatched Intelligence
      • A New Approach to Cybersecurity
      • Interactive Intelligence
      • Cyber Attack Prevention
      • Umbrella and Cisco Talos Threat Intelligence
    • Extensive Integrations
      • IT Security Integrations
      • Hardware Integrations
      • Meraki Integration
      • Cisco Umbrella and SecureX
  • Products
    • Cisco Umbrella Products
      • Cisco Umbrella Cloud Security Service
      • Recursive DNS Services
      • Cisco Umbrella SIG
      • Umbrella Investigate
      • What’s New
    • Product Packages
      • Cisco Umbrella Package Comparison
      • – DNS Security Essentials Package
      • – DNS Security Advantage Package
      • – SIG Essentials Package
      • – SIG Advantage Package
      • Umbrella Support Packages
    • Functionality
      • DNS-Layer Security
      • Secure Web Gateway
      • Cloud Access Security Broker (CASB)
      • Cloud Data Loss Prevention (DLP)
      • Cloud-Delivered Firewall
      • Cloud Malware Protection
      • Remote Browser Isolation (RBI)
    • Man on a laptop with headphones on. He is attending a Cisco Umbrella Live Demo
  • Solutions
    • SASE & SSE Solutions
      • Cisco Umbrella SASE
      • Secure Access Service Edge (SASE)
      • What is SASE
      • What is Security Service Edge (SSE)
    • Functionality Solutions
      • Web Content Filtering
      • Secure Direct Internet Access
      • Shadow IT Discovery & App Blocking
      • Fast Incident Response
      • Unified Threat Management
      • Protect Mobile Users
      • Securing Remote and Roaming Users
    • Network Solutions
      • Guest Wi-Fi Security
      • SD-WAN Security
      • Off-Network Endpoint Security
    • Industry Solutions
      • Government and Public Sector Cybersecurity
      • Financial Services Security
      • Cybersecurity for Manufacturing
      • Higher Education Security
      • K-12 Schools Security
      • Healthcare, Retail and Hospitality Security
      • Enterprise Cloud Security
      • Small Business Cybersecurity
  • Resources
    • Content Library
      • Top Resources
      • Cybersecurity Webinars
      • Events
      • Research Reports
      • Case Studies
      • Videos
      • Datasheets
      • eBooks
      • Solution Briefs
    • International Documents
      • Deutsch/German
      • Español/Spanish
      • Français/French
      • Italiano/Italian
      • 日本語/Japanese
    • For Customers
      • Support
      • Customer Success Webinars
      • Cisco Umbrella Studio
    • Get the 2022 Cloud Scurity Comparison Guide
  • Trends & Threats
    • Market Trends
      • Hybrid Workforce
      • Rise of Remote Workers
      • Secure Internet Gateway (SIG)
    • Security Threats
      • How to Stop Phishing Attacks
      • Malware Detection and Protection
      • Ransomware is on the Rise
      • Cryptomining Malware Protection
      • Cybersecurity Threat Landscape
      • Global Cyber Threat Intelligence
      • Cyber Threat Categories and Definitions
    •  
    • Woman connecting confidently to any device anywhere
  • Partners
    • Channel Partners
      • Partner Program
      • Become a Partner
    • Service Providers
      • Secure Connectivity
      • Managed Security for MSSPs
      • Managed IT for MSPs
    •  
    • Person looking down at laptop. They are connecting and working securely
  • Blog
    • News & Product Posts
      • Latest Posts
      • Products & Services
      • Customer Focus
      • Feature Spotlight
    • Cybersecurity Posts
      • Security
      • Threats
      • Cybersecurity Threat Spotlight
      • Research
    •  
    • Register for a webinar - with illustration of connecting securely to the cloud
  • Contact Us
  • Umbrella Login
  • Cloudlock Login
  • Free Trial
Products & Services

DoH! To block or not to block?

By Rachel Ackerly
Posted on September 11, 2019
Updated on March 22, 2020

Share

FacebookTweetLinkedIn

There is a lot of buzz about DoH right now. So we thought we’d just join the discussion and educate our loyal users on what all the fuss is about.

First, I’m sure you all know what DoH is — but let’s just spell it out. DoH stands for DNS-over-HTTPS, a standard published by the IETF. DoH can increase user privacy and security by preventing eavesdropping and manipulation of DNS data by man-in-the-middle attacks. Plus it can often improve performance. Sounds pretty good, right?

How does DoH work?

DoH works just like DNS, except it uses Transmission Control Protocol (TCP) to transmit and receive queries. Both take a domain name that a user types into their browser and sends a query to a DNS server to learn the numerical IP address of the web server hosting that site. The key difference is DoH takes the DNS query and sends it to a DoH-compatible DNS server (resolver) via an encrypted HTTPS connection on port 443, rather than plaintext on port 53. DoH prevents third-party observers from sniffing traffic and understanding what DNS queries users have run, or what websites users are intending to access. Since the DoH (DNS) request is encrypted, it’s even invisible to cyber-security software that relies on passive DNS monitoring to block requests to known malicious domains.

But DoH isn’t for everyone. Just because some vendors (like Mozilla) may enable DoH by default for users, doesn’t mean you have to use DoH.

Say yes or no to DoH!

Because DoH is configured on the application, the DNS servers configured by the operating system are not used. This means that the protection provided by Cisco Umbrella may be bypassed by applications using DoH. For this reason, Umbrella includes known DoH servers in the “Proxy / Anonymizer” content category. Customers can further improve coverage by also blocking Newly Seen Domains.

Additionally, Cisco Umbrella supports the “use-application-dns.net” domain as defined by Mozilla to prevent Firefox from enabling DoH by default. Note that Firefox will still enable DoH if the user manually configures a DoH server, in which case we recommend taking the steps outlined in the article below.

You can find more information on preventing the circumvention of Cisco Umbrella in our Knowledge Base.

Say yes to better cybersecurity

Most companies leave their DNS resolution up to their ISP. But as more organizations adopt direct internet connections and users bypass the VPN, this leads to a DNS-blind spot. Monitoring DNS requests, as well as subsequent IP connections is an easy way to provide better accuracy and detection of compromised systems, improving security visibility and network protection. If you’re looking for an easy way to protect your users on and off-network, check out Cisco Umbrella.

Umbrella is the fastest and easiest way to protect all of your users enterprise-wide in minutes, and reduces the number of infections and alerts you see from other security products by stopping threats at the earliest point. With no hardware to install and no software to manually update, ongoing management is simple. Don’t believe us? You can monitor your DNS traffic for FREE with DNS Monitoring.

Better visibility is just a click away »  Sign up for DNS Monitoring

Previous Post:

Previous Article

Next Post:

Next Article

Follow Us

  • Twitter
  • Facebook
  • LinkedIn
  • YouTube

Footer Sections

What we make

  • Cloud Security Service
  • DNS-Layer Network Security
  • Secure Web Gateway
  • Security Packages

Who we are

  • Global Cloud Architecture
  • Cloud Network Status
  • Cloud Network Activity
  • OpenDNS is now Umbrella
  • Cisco Umbrella Blog

Learn more

  • Webinars
  • Careers
  • Support
  • Cisco Umbrella Live Demo
  • Contact Sales
Umbrella by Cisco
208.67.222.222+208.67.220.220
2620:119:35::35+2620:119:53::53
Sign up for a Free Trial
  • Cisco Online Privacy Statement
  • Terms of Service
  • Sitemap

© 2023 Cisco Umbrella