Upstream degradation you can't see from inside
Your core is green, but one transit is blackholing traffic to a region. Probes outside your AS catch it in a minute; your customers would have caught it in a ticket.
Internal monitoring tells you your routers are up. ArgusNOC tells you whether the internet can actually reach your customers — through your upstreams, your peers, and over IPv6.
Your core is green, but one transit is blackholing traffic to a region. Probes outside your AS catch it in a minute; your customers would have caught it in a ticket.
Dual-stack customers fall back to v4 and never complain — until a v6-only service fails. Independent v6 monitoring surfaces PMTU, RA and peering issues early.
A prefix leaks, a peer withdraws, traffic takes a detour through another continent. The route graph shows the path change with AS numbers, so you know who to call.
A single flaky probe shouldn't page the on-call. Quorum rules mean an incident opens only when enough vantage points agree.
Probes run as a small agent on the hosts you already have — Linux servers, Windows boxes at POPs or customer sites.