AS_PATH
AssessTechniques
A BGP attribute that records the sequence of autonomous systems a route traverses.
Why it's here
Placed in Assess: 2 article(s) of evidence from 1 source(s), led by research-stage coverage, with 1 in the last 30 days. Confidence 35%.
Evidence (2)
- 7Cloudflare Blog·7/24/2026researchCloudflare Finds Widespread BGP ORIGIN Attribute Changes
Cloudflare reports that its measurements found around 70% of observed BGP paths across many vantage points had an ORIGIN value different from what the originating AS set. The company explains that ORIGIN is supposed to remain unchanged after injection into BGP, but altering it can influence route selection and shift traffic toward particular networks.
- 8Cloudflare Blog·6/3/2026researchCloudflare on Enforcing the First AS in BGP Paths
Cloudflare describes route hijacks that appear to rely on forged BGP AS_PATHs, including cases where attackers inserted implausible upstream ASes to misdirect traffic and hide their origin. The company argues that validating the first AS in an advertised route could help detect these attacks and says it stress-tested major networks to evaluate their BGP implementations.