This is the blog of Ronald Bartels that wanders on and off the subject of problem management (that is how it started). Like the best music is from the Eighties and a wee dram helps in solving most inconveniences.
Excessive BGP AS Path Prepending is a Self-Inflicted Vulnerability
In the Border Gateway Protocol (BGP), prepending is a technique used to
de-prioritize a route by artificially increasing the length of the
AS_PATH attribute by repeating an autonomous system number (ASN). Route
selection in BGP prefers the shorter AS path length, assuming all other
criterion are equal. Therefore, a prepended route should be selected