METHODS, SYSTEMS, AND COMPUTER READABLE MEDIA FOR AUTOMATICALLY SELECTING BETWEEN INTERNET PROTOCOL SWITCHING MODES ON A PER-MODULE BASIS IN A PACKET FORWARDING DEVICE

摘要

The subject matter described herein includes methods, systems, and computer readable media for automatically selecting between Internet protocol switching modes on a per-module basis in a packet forwarding device. According to one aspect, the subject matter described herein includes a packet forwarding device including at least one input/output (I/O) module. The at least one I/O module includes a longest prefix matching (LPM) table, an Internet protocol forwarding database (IPFDB) and the packet forwarding device includes an IP routing table and an IPFDB. When the I/O module operates in an LPM mode, the IPFDB on the I/O module is populated with entries corresponding to active hosts, the LPM table on the I/O module is populated from the IP routing table with routes learned from IP routing protocols, and layer 3 packets received by the I/O module are routed using the IPFDB and LPM table of the I/O module. An automatic mode-selection module determines a capacity of the LPM table on the I/O module. The automatic mode-selection module also determines a total number of IP routes stored in the IP routing table and determines a relationship between the total number of IP routes and the capacity of the LPM table. In response to determining that the total number of IP routes has a predetermined relationship with the capacity of the LPM table, the automatic mode-selection module also automatically switches the I/O module from the LPM mode to an IPFDB mode, where the IPFDB and the LPM table are populated with entries corresponding to active hosts and layer 3 packets received by the I/O module are routed using the IPFDB and LPM table of the I/O module.