Binary search schemes for fast IP lookups
Pronita Mehrotra, Paul D. Franzon · 2004
Route lookup is becoming a very challenging problem due to the increasing size of routing tables. To determine the outgoing port for a given address, the longest matching prefix among all the prefixes, needs to be determined. This makes the task of searching in a large database quite difficult. Our paper describes binary search schemes that allow fast address lookups. Binary search can be performed on the number of entries or on the number of mutually disjoint prefixes. Lookups can be performed in O(N) time, where N is number of entries and the amount of memory required to store the binary database is also O(N). These schemes scale very well with both large databases and for longer addresses (as in IPv6).