When using Meraki MX Content Filtering Powered by Cisco Talos, customers may face inconsistencies with some Umbrella DNS filtering features.
- Incorrect block page (custom block pages not applied)
- Block page bypass feature not displayed
- "401 Unauthorized" error for sites using Intelligent Proxy
- Policy-Debug tests show incorrect Org / Origin ID/ BundleID
Exclude the following domain from Meraki MX content filtering feature using the "Allowed URL" list on the Meraki Dashboard.
The content filtering is configured in the following places on the Meraki Dashboard:
- In 'Security & SD-WAN > Content Filtering' (Global settings)
- In 'Network-wide > Group policies' (Policies that can be assigned to users or SSIDs)
Alternatively, disable Meraki content filtering completely (remove all category blocks) to use Umbrella filtering only.
Cisco Umbrella uses a globally unique redirect to http://*.id.opendns.com when traffic first arrives at our Block Page Landers, Intelligent Proxy, or Policy-Debug sites. This redirect is required to generate a globally unique DNS lookup. This unique DNS allows us to authenticate traffic at the DNS layer and in turn determine the correct user/device/network identity.
Meraki MX Content Filtering performs it's own reputation checks. When the http://*.id.opendns.com is visited the Meraki MX content filtering may generate duplicate DNS lookups for the same domain which breaks this authentication process. Therefore Cisco Umbrella is unable to determine the correct user/device/network identity.
This problem does not prevent Cisco Umbrella enforcing content/security blocks but does prevent the correct block page text/logo/customization from being displayed.
This behavior can also be caused with on-premise HTTP web proxies / web filters. Mandatory configuration steps are required for Using Umbrella DNS with a HTTP proxy.
Example: Policy-Debug example
An indicator of this issue is when the information on the http://policy-debug.checkumbrella.com shows an incorrect Org ID. The ID may be displayed as '0', '2', or an ID which is not associated with the expected org.
Org ID: 0. <<<<<. Incorrect Org ID
Bundle ID: XXXX
Origin ID: XXXX
Internal IP: x.x.x.x
Time: Fri, 29 Sep 2023 16:16:22.182335 UTC
Example: Intelligent Proxy
An indicator of this issue is when the iproxy server returns an unexpected '401' for some sites (including http://proxy.opendnstest.com) even when the customer is licensed for Intelligent proxy. Note that the error is returned from server.
Note that Intelligent Proxy is only used for some sites that have a 'grey' or suspicious reputation so the issue will only appear in specific circumstances.
Example: Block Pages
An indicator of this issue is when the block page does not display any org-specific customization. The block page is still displayed but contains the default 'Cisco Umbrella' branding instead of custom logos/text. Block page bypass users/codes will be missing.