Super Traceroute

Traceroute is a network diagnostic tool that maps the path packets take from your machine to a destination host. It sends packets with incrementally increasing TTL (Time To Live) values. Each router decrements the TTL and, when it reaches zero, returns an ICMP "time exceeded" message, revealing that router's IP address and round-trip time.

An Autonomous System (AS) is a collection of IP networks under the control of a single organization with a unified routing policy. Each AS has a globally unique ASN (Autonomous System Number). The internet is essentially a network of ASes connected via BGP (Border Gateway Protocol). Every traceroute hop that crosses an AS boundary represents your traffic moving between different network operators.

The AS-PATH shows which autonomous systems your traffic traverses. A short AS-PATH (2–3 ASes) means well-peered networks with direct connections. Many AS hops may indicate indirect routing through transit providers. Traffic between major CDNs and cloud providers often stays within 1–2 AS hops due to extensive private peering agreements.

A hop showing * means no ICMP response was received within the timeout period. This can mean the router rate-limits or drops ICMP packets for security reasons, the packet was lost, or the router is configured not to respond to TTL-exceeded messages. Silent hops are common in large ISP backbone networks and do not necessarily indicate a problem.

BGP (Border Gateway Protocol) is the routing protocol that connects autonomous systems across the internet. It exchanges reachability information between ASes, allowing routers to determine the best path to any destination. BGP is policy-based: operators prefer routes based on peering agreements, cost, and performance rather than just hop count or latency.