Why are rainbow table attacks ineffective against Linux password hashes?

Rainbow tables rely on precomputed hash tables for unsalted passwords. Linux password hashes include a unique, random salt for each user, which alters the final hash even if two users share the same password. This salt renders precomputed tables useless, forcing attackers to use dictionary or brute-force attacks. The Linux Password Hashes article explains how the salt is embedded in the hash format (e.g., `$6$C/vGzhVe$`).