Pulse — AS-path anomaly
Unique-AS-path lengths (prepends collapsed) that deviate sharply from the recent 36-hour median for that prefix.
What is AS-path anomaly?
An AS-path anomaly is an unusual or implausible sequence of Autonomous Systems in a route advertisement whose unique-AS-path length (prepends collapsed) deviates sharply from the recent 36-hour median for that prefix — an unexpected transit AS, a loop, or a sudden detour. It can reveal a route leak or a path-prepending mistake.
Geographic distribution
Flagged events
Showing 200 most recent of 1,003 · last 24h| When | Severity | Prefix | AS |
|---|---|---|---|
| Aug 29, 23:57 UTC | 56 | 145.237.0.0/17 | AS34339 |
| Aug 29, 23:57 UTC | 56 | 195.136.78.0/24 | AS199260 |
| Aug 29, 23:57 UTC | 56 | 185.22.136.0/22 | AS199057 |
| Aug 29, 23:57 UTC | 58 | 177.124.32.0/22 | AS52861 |
| Aug 29, 23:57 UTC | 58 | 177.93.144.0/22 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 81.15.217.0/24 | AS205990 |
| Aug 29, 23:57 UTC | 56 | 145.237.128.0/17 | AS34339 |
| Aug 29, 23:57 UTC | 56 | 188.172.244.0/24 | AS42473 |
| Aug 29, 23:57 UTC | 56 | 103.26.37.0/24 | AS133064 |
| Aug 29, 23:57 UTC | 56 | 195.136.158.0/23 | AS199260 |
| Aug 29, 23:57 UTC | 56 | 45.130.210.0/24 | AS34903 |
| Aug 29, 23:57 UTC | 56 | 5.2.48.0/21 | AS41560 |
| Aug 29, 23:57 UTC | 56 | 195.69.209.0/24 | AS25070 |
| Aug 29, 23:57 UTC | 56 | 104.23.231.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 56 | 151.96.0.0/16 | AS8217 |
| Aug 29, 23:57 UTC | 58 | 177.93.148.0/22 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 1.55.63.0/24 | AS18403 |
| Aug 29, 23:57 UTC | 56 | 185.202.126.0/24 | AS198595 |
| Aug 29, 23:57 UTC | 58 | 177.93.146.0/23 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 194.41.12.0/22 | AS25495 |
| Aug 29, 23:57 UTC | 56 | 46.8.210.0/24 | AS204490 |
| Aug 29, 23:57 UTC | 56 | 157.25.57.0/24 | AS206770 |
| Aug 29, 23:57 UTC | 56 | 193.178.132.0/24 | AS29536 |
| Aug 29, 23:57 UTC | 56 | 109.94.250.0/24 | AS50086 |
| Aug 29, 23:57 UTC | 56 | 104.22.132.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 56 | 91.210.130.0/24 | AS44279 |
| Aug 29, 23:57 UTC | 56 | 45.226.107.0/24 | AS267013 |
| Aug 29, 23:57 UTC | 56 | 195.136.76.0/24 | AS202403 |
| Aug 29, 23:57 UTC | 56 | 104.22.133.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 56 | 103.90.202.0/24 | AS136503 |
| Aug 29, 23:57 UTC | 56 | 104.23.215.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 56 | 45.12.99.0/24 | AS47576 |
| Aug 29, 23:57 UTC | 56 | 88.220.138.0/24 | AS210587 |
| Aug 29, 23:57 UTC | 56 | 109.94.241.0/24 | AS50086 |
| Aug 29, 23:57 UTC | 56 | 138.0.6.0/24 | AS264527 |
| Aug 29, 23:57 UTC | 56 | 145.237.192.0/19 | AS34339 |
| Aug 29, 23:57 UTC | 56 | 185.184.126.0/24 | AS198704 |
| Aug 29, 23:57 UTC | 58 | 177.124.34.0/23 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 91.209.153.0/24 | AS41253 |
| Aug 29, 23:57 UTC | 56 | 144.208.220.0/24 | AS42473 |
| Aug 29, 23:57 UTC | 56 | 185.202.127.0/24 | AS198595 |
| Aug 29, 23:57 UTC | 56 | 185.151.75.0/24 | AS47322 |
| Aug 29, 23:57 UTC | 56 | 139.135.220.0/22 | AS56207 |
| Aug 29, 23:57 UTC | 56 | 145.237.160.0/19 | AS34339 |
| Aug 29, 23:57 UTC | 58 | 177.124.38.0/23 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 91.218.196.0/22 | AS51393 |
| Aug 29, 23:57 UTC | 56 | 185.247.252.0/24 | AS200369 |
| Aug 29, 23:57 UTC | 56 | 88.220.71.0/24 | AS199694 |
| Aug 29, 23:57 UTC | 56 | 45.130.208.0/24 | AS34903 |
| Aug 29, 23:57 UTC | 56 | 45.130.209.0/24 | AS34903 |
| Aug 29, 23:57 UTC | 56 | 45.227.230.0/24 | AS271704 |
| Aug 29, 23:57 UTC | 56 | 14.238.12.0/24 | AS45899 |
| Aug 29, 23:57 UTC | 58 | 177.124.36.0/22 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 91.236.57.0/24 | AS198595 |
| Aug 29, 23:57 UTC | 56 | 185.151.74.0/24 | AS47322 |
| Aug 29, 23:57 UTC | 56 | 5.2.32.0/21 | AS41560 |
| Aug 29, 23:57 UTC | 56 | 91.198.194.0/24 | AS43867 |
| Aug 29, 23:57 UTC | 56 | 109.94.245.0/24 | AS50086 |
| Aug 29, 23:57 UTC | 56 | 194.49.104.0/24 | AS56373 |
| Aug 29, 23:57 UTC | 56 | 194.35.236.0/23 | AS49007 |
| Aug 29, 23:57 UTC | 56 | 5.2.58.0/23 | AS41560 |
| Aug 29, 23:57 UTC | 56 | 145.237.0.0/16 | AS34339 |
| Aug 29, 23:57 UTC | 56 | 88.220.90.0/24 | AS212305 |
| Aug 29, 23:57 UTC | 56 | 193.105.20.0/24 | AS50423 |
| Aug 29, 23:57 UTC | 56 | 193.108.177.0/24 | AS47322 |
| Aug 29, 23:57 UTC | 56 | 185.202.124.0/24 | AS198595 |
| Aug 29, 23:57 UTC | 56 | 78.41.24.0/21 | AS48022 |
| Aug 29, 23:57 UTC | 56 | 88.220.88.0/24 | AS215652 |
| Aug 29, 23:57 UTC | 56 | 91.217.228.0/24 | AS24732 |
| Aug 29, 23:57 UTC | 56 | 213.199.213.0/24 | AS25070 |
| Aug 29, 23:57 UTC | 56 | 88.220.51.0/24 | AS209296 |
| Aug 29, 23:57 UTC | 56 | 195.238.245.0/24 | AS34730 |
| Aug 29, 23:57 UTC | 56 | 31.132.64.0/21 | AS56945 |
| Aug 29, 23:57 UTC | 56 | 104.22.60.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 56 | 109.94.249.0/24 | AS50086 |
| Aug 29, 23:57 UTC | 56 | 14.168.12.0/24 | AS45899 |
| Aug 29, 23:57 UTC | 56 | 120.28.28.0/24 | AS23689 |
| Aug 29, 23:57 UTC | 56 | 104.22.48.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 58 | 177.93.148.0/23 | AS52861 |
| Aug 29, 23:57 UTC | 58 | 177.124.32.0/21 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 109.94.248.0/24 | AS50086 |
| Aug 29, 23:57 UTC | 56 | 145.237.4.0/24 | AS34339 |
| Aug 29, 23:57 UTC | 56 | 88.220.82.0/23 | AS201904 |
| Aug 29, 23:57 UTC | 56 | 213.227.180.0/24 | AS42473 |
| Aug 29, 23:57 UTC | 56 | 193.16.107.0/24 | AS31528 |
| Aug 29, 23:57 UTC | 56 | 5.100.247.0/24 | AS204128 |
| Aug 29, 23:57 UTC | 56 | 92.63.32.0/20 | AS49633 |
| Aug 29, 23:57 UTC | 56 | 88.220.84.0/24 | AS204301 |
| Aug 29, 23:57 UTC | 56 | 185.255.252.0/22 | AS199390 |
| Aug 29, 23:57 UTC | 56 | 194.113.249.0/24 | AS211295 |
| Aug 29, 23:57 UTC | 62 | 204.157.236.0/24 | AS174 |
| Aug 29, 23:57 UTC | 56 | 185.18.132.0/22 | AS199390 |
| Aug 29, 23:57 UTC | 56 | 5.2.44.0/22 | AS41560 |
| Aug 29, 23:57 UTC | 56 | 217.79.144.0/23 | AS42923 |
| Aug 29, 23:57 UTC | 56 | 88.199.162.0/24 | AS42923 |
| Aug 29, 23:57 UTC | 56 | 91.235.16.0/22 | AS204295 |
| Aug 29, 23:57 UTC | 56 | 5.254.184.0/21 | AS199205 |
| Aug 29, 23:57 UTC | 56 | 185.41.94.0/23 | AS199953 |
| Aug 29, 23:57 UTC | 56 | 5.2.56.0/24 | AS41560 |
| Aug 29, 23:57 UTC | 56 | 196.22.240.0/20 | AS36874 |
| Aug 29, 23:57 UTC | 56 | 195.136.12.0/23 | AS199260 |
| Aug 29, 23:57 UTC | 56 | 217.79.146.0/23 | AS42923 |
| Aug 29, 23:57 UTC | 56 | 145.237.224.0/19 | AS34339 |
| Aug 29, 23:57 UTC | 56 | 120.28.29.0/24 | AS23689 |
| Aug 29, 23:57 UTC | 56 | 5.2.57.0/24 | AS41560 |
| Aug 29, 23:57 UTC | 58 | 177.93.144.0/21 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 46.8.208.0/22 | AS204490 |
| Aug 29, 23:57 UTC | 56 | 138.186.239.0/24 | AS264527 |
| Aug 29, 23:57 UTC | 56 | 85.190.245.0/24 | AS41455 |
| Aug 29, 23:57 UTC | 56 | 185.41.92.0/24 | AS199953 |
| Aug 29, 23:57 UTC | 56 | 109.94.240.0/20 | AS50086 |
| Aug 29, 23:57 UTC | 56 | 193.238.200.0/22 | AS35198 |
| Aug 29, 23:57 UTC | 56 | 109.94.242.0/24 | AS50086 |
| Aug 29, 23:57 UTC | 56 | 46.148.132.0/22 | AS44056 |
| Aug 29, 23:57 UTC | 56 | 194.49.106.0/24 | AS56373 |
| Aug 29, 23:57 UTC | 56 | 195.136.176.0/22 | AS199390 |
| Aug 29, 23:57 UTC | 56 | 104.23.216.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 56 | 5.172.190.0/23 | AS207012 |
| Aug 29, 23:57 UTC | 56 | 104.22.134.0/24 | AS13335 |
| Aug 29, 23:57 UTC | 56 | 195.182.52.0/24 | AS47322 |
| Aug 29, 23:57 UTC | 56 | 185.32.48.0/24 | AS200244 |
| Aug 29, 23:57 UTC | 56 | 145.237.3.0/24 | AS34339 |
| Aug 29, 23:57 UTC | 56 | 91.212.86.0/24 | AS48963 |
| Aug 29, 23:57 UTC | 58 | 177.124.36.0/23 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 196.41.96.0/19 | AS36874 |
| Aug 29, 23:57 UTC | 56 | 194.145.229.0/24 | AS34212 |
| Aug 29, 23:57 UTC | 56 | 5.2.55.0/24 | AS41560 |
| Aug 29, 23:57 UTC | 56 | 194.165.54.0/24 | AS39243 |
| Aug 29, 23:57 UTC | 56 | 185.96.8.0/22 | AS200792 |
| Aug 29, 23:57 UTC | 56 | 88.220.55.0/24 | AS213530 |
| Aug 29, 23:57 UTC | 56 | 193.35.36.0/24 | AS198937 |
| Aug 29, 23:57 UTC | 56 | 80.241.128.0/21 | AS16296 |
| Aug 29, 23:57 UTC | 56 | 5.2.60.0/22 | AS41560 |
| Aug 29, 23:57 UTC | 56 | 88.220.72.0/24 | AS199823 |
| Aug 29, 23:57 UTC | 58 | 177.124.32.0/23 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 14.238.9.0/24 | AS45899 |
| Aug 29, 23:57 UTC | 56 | 105.233.0.0/16 | AS36874 |
| Aug 29, 23:57 UTC | 58 | 177.93.144.0/23 | AS52861 |
| Aug 29, 23:57 UTC | 56 | 195.136.108.0/24 | AS215903 |
| Aug 29, 23:57 UTC | 56 | 195.136.2.0/23 | AS51393 |
| Aug 29, 23:57 UTC | 56 | 45.130.208.0/22 | AS34903 |
| Aug 29, 22:57 UTC | 62 | 120.50.61.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 60 | 120.50.60.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 60 | 103.238.124.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 56 | 102.222.62.0/24 | AS328749 |
| Aug 29, 22:57 UTC | 56 | 91.231.178.0/24 | AS52142 |
| Aug 29, 22:57 UTC | 60 | 120.50.50.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 56 | 91.197.148.0/22 | AS30975 |
| Aug 29, 22:57 UTC | 56 | 177.177.80.0/23 | AS204921 |
| Aug 29, 22:57 UTC | 60 | 120.50.63.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 56 | 176.119.217.0/24 | AS215385 |
| Aug 29, 22:57 UTC | 56 | 83.145.128.0/18 | AS30975 |
| Aug 29, 22:57 UTC | 56 | 164.160.44.0/23 | AS328032 |
| Aug 29, 22:57 UTC | 60 | 103.238.126.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 60 | 120.50.53.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 60 | 120.50.54.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 56 | 8.31.32.0/20 | AS395368 |
| Aug 29, 22:57 UTC | 56 | 104.18.32.0/19 | AS13335 |
| Aug 29, 22:57 UTC | 56 | 185.13.144.0/22 | AS49633 |
| Aug 29, 22:57 UTC | 56 | 164.160.46.0/23 | AS328032 |
| Aug 29, 22:57 UTC | 60 | 120.50.58.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 60 | 120.50.51.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 60 | 120.50.57.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 56 | 91.210.131.0/24 | AS44279 |
| Aug 29, 22:57 UTC | 60 | 120.50.56.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 56 | 74.114.155.0/24 | AS2635 |
| Aug 29, 22:57 UTC | 56 | 160.20.24.0/22 | AS328032 |
| Aug 29, 22:57 UTC | 56 | 89.238.0.0/18 | AS41356 |
| Aug 29, 22:57 UTC | 60 | 120.50.59.0/24 | AS132196 |
| Aug 29, 22:57 UTC | 56 | 38.190.110.0/24 | AS212616 |
| Aug 29, 22:57 UTC | 56 | 91.216.202.0/24 | AS197135 |
| Aug 29, 22:57 UTC | 60 | 120.50.52.0/24 | AS132196 |
| Aug 29, 21:57 UTC | 56 | 88.220.164.0/24 | AS209388 |
| Aug 29, 21:57 UTC | 56 | 176.112.92.0/22 | AS49124 |
| Aug 29, 21:57 UTC | 56 | 185.106.168.0/22 | AS49633 |
| Aug 29, 21:57 UTC | 56 | 81.15.246.0/24 | AS25070 |
| Aug 29, 21:57 UTC | 56 | 193.200.216.0/24 | AS43062 |
| Aug 29, 21:57 UTC | 56 | 195.150.192.0/22 | AS203890 |
| Aug 29, 21:57 UTC | 56 | 158.66.6.0/24 | AS21111 |
| Aug 29, 21:57 UTC | 56 | 193.28.0.0/24 | AS30730 |
| Aug 29, 21:57 UTC | 56 | 194.106.210.0/23 | AS31412 |
| Aug 29, 21:57 UTC | 56 | 158.66.0.0/16 | AS21111 |
| Aug 29, 21:57 UTC | 56 | 81.15.237.0/24 | AS203279 |
| Aug 29, 21:57 UTC | 56 | 193.238.64.0/22 | AS31412 |
| Aug 29, 21:57 UTC | 56 | 193.56.70.0/24 | AS25070 |
| Aug 29, 21:57 UTC | 56 | 188.164.144.0/21 | AS31608 |
| Aug 29, 21:57 UTC | 56 | 192.68.51.0/24 | AS198743 |
| Aug 29, 21:57 UTC | 56 | 82.177.201.0/24 | AS42246 |
| Aug 29, 21:57 UTC | 56 | 82.177.195.0/24 | AS197142 |
| Aug 29, 21:57 UTC | 56 | 82.177.202.0/23 | AS206442 |
| Aug 29, 21:57 UTC | 56 | 82.177.100.0/24 | AS43769 |
| Aug 29, 21:57 UTC | 56 | 195.136.121.0/24 | AS204412 |
| Aug 29, 21:57 UTC | 56 | 158.66.2.0/24 | AS21111 |
| Aug 29, 21:57 UTC | 56 | 158.66.4.0/24 | AS21111 |
| Aug 29, 21:57 UTC | 56 | 85.198.248.0/22 | AS208556 |
| Aug 29, 21:57 UTC | 56 | 194.50.110.0/24 | AS39661 |
| Aug 29, 21:57 UTC | 56 | 81.15.218.0/24 | AS207764 |
| Aug 29, 21:57 UTC | 56 | 158.66.5.0/24 | AS21111 |
| Aug 29, 21:57 UTC | 56 | 195.238.168.0/22 | AS56709 |
| Aug 29, 21:57 UTC | 56 | 193.29.205.0/24 | AS31229 |
Frequently Asked Questions
What is a BGP AS-path anomaly?
An AS-path anomaly is an unusual or implausible sequence of Autonomous Systems in a route advertisement whose unique-AS-path length (prepends collapsed) deviates sharply from the recent 36-hour median for that prefix — an unexpected transit AS, a loop, or a sudden detour. It can reveal a route leak or a path-prepending mistake.
Where does this data come from?
Every event is detected from live BGP updates collected across 23 RIPE RIS route collectors worldwide, ingested into a ClickHouse time-series store and re-evaluated every few minutes. No third-party feed is resold; the analysis is original to WorldIP.io.
How often is the AS-path anomaly feed updated?
The feed recomputes roughly every 5 minutes; it was last refreshed at 2026-08-30 00:25 UTC.
How do I subscribe to AS-path anomaly events?
Subscribe to the Atom feed at /pulse/bgp/aspath.atom or poll the JSON endpoint at /api/pulse/bgp/aspath.