The probe maps HTTP status codes into four discrete buckets: 2xx and 3xx evaluate to live, 4xx evaluate to gone, 5xx evaluate to server_error, and timeouts, connection failures, or SSRF-blocked requests evaluate to dead.

flowchart LR
    A[HTTP Response] --> B{Status Code}
    B -->|2xx / 3xx| C[live: Keep link]
    B -->|4xx| D[gone: Strip link]
    B -->|5xx| E[server_error: Strip link]
    B -->|None / Blocked| F[dead: Strip link]