Nothing replaces it. Lookup performance of the routing table has been increased by using an LC trie since 2.6.39 and the various information which were previous

Nothing replaces it. Lookup performance of the routing table has been increased by using an LC trie since 2.6.39 and the various information which were previously in the cache have been moved to other structures. The performance of the cache was said to be bad (only 10% hit, but that doesn't match at all my experience where the performances of the cache were pretty good, see the article) and being an hash table, it was the target of DOS attacks. Moreover, many information were tied to the cache, triggering some additional problems, like the "neighbor cache overflow".