Cisco Umbrella works at the (and can also proxy traffic). When you try to visit a blocked site, Umbrella returns a different IP address — usually a block page — instead of the real site’s IP.
However, no security filter is perfect. Occasionally, legitimate business websites get caught in the crossfire—a phenomenon known as a "False Positive." When this happens, users are greeted with a "Block Page," and productivity grinds to a halt. cisco umbrella unblock
Even after you whitelist a domain in Umbrella, the user’s computer remembers the previous "bad" IP address (or the browser cached the block page). Cisco Umbrella works at the (and can also proxy traffic)
The most common way to unblock a site is by adding it to a . In Cisco Umbrella, Destination Lists are used to override the default security settings. Occasionally, legitimate business websites get caught in the