TECHNIQUE TO IMPROVE NETWORK ROUTING USING BEST-MATCH AND EXACT-MATCH TECHNIQUES
 Information may be sent through a network using a network address. For example, a router may receive information that is to be routed to another network device. The router may use a network address, such as a destination address, to search for the appropriate routing information. As address sizes increase and the size of networks increase, additional time is required for the router to access routing tables in memory and search for the routing information. Therefore, there is a need to reduce search time for routing information and thereby improve packet forwarding speed.
BRIEF DESCRIPTION OF THE DRAWINGS
 The subject matter regarded as embodiments of the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. Embodiments of the invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
 FIG. 1 is an example system suitable for practicing one embodiment of the invention;
 FIG. 2 is a block diagram of an example routing system in accordance with one embodiment of the invention;
 FIG. 3 illustrates an example address format suitable for use with one embodiment of the invention;
 FIG. 4 is a block flow diagram of processing logic which may be performed by a routing system in accordance with one embodiment of the invention.
 FIG. 5 is a block flow diagram of processing logic which may be performed by a routing system in accordance with one embodiment of the invention.
 FIG. 6 illustrates an example use of tables to search for routing information in accordance with one embodiment of the invention.
 FIG. 7 illustrates another example use of an LPM technique and a hash technique to search for routing information in accordance with one embodiment of the invention.
 Embodiments of the invention may comprise a method and apparatus to improve the routing of information over a network. As information travels through a network from a source to a particular destination, a number of network devices may need to search for routing information. The search may use a network address. The latency associated with a search may be directly related to the size of the network address. Typically, the more bits used to represent a network address the more memory accesses needed to search for routing information. Many routers perform a Longest Prefix Match (LPM) on the entire address to search for routing information. But this technique typically requires a large number of memory accesses, especially for larger addresses. These memory accesses can result in significant
packet delay. There may be a need for a technique that allows searching for routing information while reducing the number of memory accesses and packet delay.
 It is worthy to note that any reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.
 Numerous specific details may be set forth herein to provide a thorough understanding of the embodiments of the invention. It will be understood by those skilled in the art, however, that the embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the embodiments of the invention. It can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the invention.
 A method and apparatus to search for routing information is described. According to an embodiment, a packet is received that includes an address. The address includes a first section and a second section. According to an embodiment, technique is described to search for routing information that uses a first technique on at least a portion of the first section of an address and a second technique on at least a portion of the second section of the address. In one embodiment, a best-match technique is used on at least a portion of the first section of the address and an exact-match technique is used on a portion of the second section of the address. The best-match technique may comprise, for example, a LPM technique. The exact-match technique may comprise, for example, a hashing algorithm or use of a Content Addressable Memory (CAM) or the like.
 In one embodiment, a packet may be received. The packet may include a destination address. The destination address may include several sections, including a topology or network section (describing the network or network topology) and an interface ID or host section (describing the host or host interface). The term interface ID may be used herein to describe a portion of an address corresponding or describing a host or node interface/host interface. Thus, the terms host section and interface ID may be used interchangeably.
 In one embodiment, the interface ID may have a globally unique value, and may be the same as or based upon a globally unique link-layer address. A routing system may search for routing information for the packet by using a LPM technique on at least a portion of the topology section of the address, and by using a hashing technique on the interface ID or host section of the address. In some embodiments, the routing system may perform a hash lookup on the interface ID only if additional routing information can be found using the interface ID or if a result of the LPM satisfies a specific condition. By performing a LPM on a first section of an address and then performing an exact-match (such as hash) on a second section of the address, fewer memory accesses may be required to find routing information.
 Referring now in detail to the drawings wherein like parts are designated by like reference numerals through