Read an observed AS path without treating it as a map of commercial contracts or the packet path your application used.
Read the collector’s evidence
Open an ASN’s observed-neighbor section, such as AS13335 connectivity, then follow a prefix to its BGP path observations. The collector, peer and observation time define the viewpoint.
Adjacency is an observation
For the illustrative sequence A → B → C, the data supports observed adjacency between A and B and between B and C. It does not reveal whether B sells transit to C, exchanges settlement-free traffic or participates in another arrangement. PJHTech leaves that relationship unknown when no separately sourced classification is available.
Prepending and ambiguous paths
Repeated consecutive AS numbers can be collapsed for the neighbor view while the raw path remains available. An unordered set, confederation segment or malformed ending cannot safely be forced into a single origin. Check raw evidence when the summarized path is incomplete.
Compare like with like
Inspect IPv4 and IPv6 independently, using comparable snapshot ages. A neighbor observed in one family need not appear in the other. Even a shared exchange or facility would establish only a possible meeting place, not a confirmed peering session.
When you need a packet test
Use Looking Glass to investigate reachability from an actual measurement source. Traceroute hop addresses and BGP AS paths answer different questions; tunnels, filtering and return paths can make their apparent sequences differ. Do not turn either result into a complete physical topology claim.