Extra alert information for the "single homed prefix" alert
This alert triggers when a prefix goes having more than multiple upstreams or not existing, to having only a single upstream.
You can find out more about what bgp.tools considers a upstream here
Two graphs are displayed to assist in debugging, one with a title that says “Before” that shows what bgp.tools knew about the prefix before it went single homed, and a graph of the propergation at the time the alert was processed.
This alert can take some time to fire, as it uses a different data source to most BGP alerts. The date on the top of the graphs should let you know when bgp.tools processed each routing snapshot