On: We will be retiring Alexa.com

[lgats]

Initially, it was mostly by monitoring the traffic of users of the alexa toolbar, https://www.alexa.com/toolbar

I think they moved on to more broad data sources, possibly purchasing data from ISPs.

[fragmede → lgats]

Read between the lines as to how this similar product from Cisco works.

http://s3-us-west-1.amazonaws.com/umbrella-static/index.html

[smarx007 → fragmede]

Thanks! Goodness, only raised more questions:

1. What is Umbrella? See http://info.opendns.com/rs/033-OMP-861/images/OpenDNS-Global...

2. What is Passive DNS? See https://docs.umbrella.com/investigate-ui/docs/passive-dns