hierarchical architecture
- Tier-1 ISP → Tier-2 ISP → Tier-3 ISP → Local ISP
graph TD T1A[Tier 1 ISP A] T1B[Tier 1 ISP B] T2A[Tier 2 ISP A] T2B[Tier 2 ISP B] T3A[Local ISP A] T3B[Local ISP B] T3A -->|transit| T2A T3B -->|transit| T2B T2A -->|transit| T1A T2B -->|transit| T1B T1A <-->|peering| T1B T2A <-->|peering| T2B classDef tier1 fill:#ff9999 classDef tier2 fill:#99ff99 classDef tier3 fill:#9999ff class T1A,T1B tier1 class T2A,T2B tier2 class T3A,T3B tier3
Use traceroute for finding probes between transit