Watch who announces your prefix, how much of the internet sees it, what transit carries it, and whether a ROA authorises the announcement.
Name the autonomous systems entitled to announce your network. Anything else originating it is reported as a hijack, and so is a longer prefix announced inside yours by another AS — the more-specific route wins, so it diverts traffic whatever you announce.
Visibility is measured across RIPE’s global collectors, so a prefix that has stopped propagating to part of the internet shows up as a number rather than as scattered reports from users who cannot reach you.
Transit providers and AS path length are tracked and reported, but never take the monitor down. A transit migration is planned work, and denting your uptime for it would make the whole board less trustworthy.
Validation runs against the AS currently originating the prefix, distinguishing an unauthorised origin from an announcement longer than the ROA allows. A missing ROA is reported too, because without one nothing separates your announcement from somebody claiming it.
When the routing data is unavailable the check reads as unverified, never as an outage. Silence about the global routing table is not evidence your prefix is gone, and reporting it as one would page you at three in the morning for somebody else’s API being slow.