+choice
+ prompt "Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure)"
+ depends on IP_ADVANCED_ROUTER
+ default IP_FIB_HASH
+
+config IP_FIB_HASH
+ bool "FIB_HASH"
+ ---help---
+ Current FIB is very proven and good enough for most users.
+
+config IP_FIB_TRIE
+ bool "FIB_TRIE"
+ ---help---
+ Use new experimental LC-trie as FIB lookup algoritm.
+ This improves lookup performance if you have a large
+ number of routes.
+
+ LC-trie is a longest matching prefix lookup algorithm which
+ performs better than FIB_HASH for large routing tables.
+ But, it consumes more memory and is more complex.
+
+ LC-trie is described in:
+
+ IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+ IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+ An experimental study of compression methods for dynamic tries
+ Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
+ http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
+
+endchoice
+
+# If the user does not enable advanced routing, he gets the safe
+# default of the fib-hash algorithm.
+config IP_FIB_HASH
+ bool
+ depends on !IP_ADVANCED_ROUTER
+ default y
+