what is ip reputation?
a score a site assigns your exit address from its history, network type and current behaviour, used to decide whether to serve, challenge or block you.
commercial feeds and the large cdns keep a record per address: which asn it belongs to, whether it is known hosting or a known vpn exit, whether it has sent spam or hit honeypots, how many distinct accounts have logged in from it lately, how fast it is requesting right now. that score is consulted at the edge, so it decides your outcome before your request reaches any application code. three consequences follow. reputation is shared, so what other people do from the same address, and often the same subnet, lands on you. it decays rather than resets, so a burned ip recovers slowly if at all. and bursts are what damage it, so pacing protects your own future access more than any header trick. no provider can sell permanently clean reputation. what a good provider sells is a pool large enough that each exit is used lightly.