Abstract: The subject matter described herein includes methods and systems for conserving multicast port lists in an IP packet forwarding device. According to one embodiment, the method includes providing an IP multicast packet port data structure containing at least a first port list and a second port list. The first and second port lists each contain zero or more port addresses for indicating the ports to which a received IP multicast packet including a group IP address is to be forwarded. An IP multicast packet forwarding database (FDB) is provided where the FDB has at least a first FDB entry and a second FDB entry for forwarding the received IP multicast packet based on its group IP address. The first and second FDB entries each include at least one multicast group IP address and are associated with at least one of the first and the second port lists. It is then determined whether the first and second port lists contain identical information.

Abstract: The subject matter described herein includes methods and systems for providing accidental stack join protection. According to one embodiment, a method includes connecting stacking ports of a first switch that is a member of a first stack and a second switch that is a member of a second stack and thereby joining the first and second stacks. The configurations of the first stack and of the second stack are detected and it is determined whether the detected configurations indicate a configuration mismatch between the first and second stacks. In response to determining that the detected configurations relate to a mismatch, the automatic joining of the first and second stacks is inhibited and the first and second stacks are allowed to continue switching traffic with their existing configurations.

Abstract: Methods and systems for hybrid layer 2 address learning are disclosed. In one method, a packet with a layer 2 source address is received. Next, it is determined whether to implement hardware-based learning or software-based learning based on a classification of the received packet. In response to determining that software-based learning is required, the source address and corresponding forwarding information in the packet are learned using software. In response to determining that hardware-based learning is required, the source address and corresponding forwarding information are learned using hardware.

Abstract: Methods and systems for hitless switch management module failover and upgrade are disclosed. According to one method, a master switch management module participates in network protocols and performs packet forwarding operations. The master switch management module distributes protocol state and packet forwarding information to the slave switch management module. The slave switch management module continuously monitors the operational state of the master switch management module. In response to detecting failure of the master switch management module or a forced failover initiated by the user interface on the master switch management module, the slave switch management module begins network protocol operation in the master mode in a state where the master switch management module last operated correctly.

Abstract: The subject matter described herein includes methods and systems for providing accidental stack join protection. According to one embodiment, a method includes connecting stacking ports of a first switch that is a member of a first stack and a second switch that is a member of a second stack and thereby joining the first and second stacks. The configurations of the first stack and of the second stack are detected and it is determined whether the detected configurations indicate a configuration mismatch between the first and second stacks. In response to determining that the detected configurations relate to a mismatch, the automatic joining of the first and second stacks is inhibited and the first and second stacks are allowed to continue switching traffic with their existing configurations.

Abstract: A method for hitless restart of layer 3 packet forwarding includes replicating some but not all state information from a master management service module to a slave management service module. The master management service module builds a layer 3 routing table by participating in layer 3 routing protocols. The layer 3 routing table is stored in memory. The master management service module builds a first layer 3 forwarding table and stores the forwarding information in hardware. A slave management service module receives a copy of the first layer 3 forwarding table from the master management service module. When the master management service module fails, the slave management service module initiates construction of a routing table by participating in layer 3 routing protocols. Packet forwarding is not interrupted because forwarding using hardware entries continues. The slave management service module links entries in the newly constructed routing table to those stored in the forwarding table.

Abstract: A method for hitless restart of layer 3 packet forwarding includes replicating some but not all state information from a master management service module to a slave management service module. The master management service module builds a layer 3 routing table by participating in layer 3 routing protocols. The layer 3 routing table is stored in memory. The master management service module builds a first layer 3 forwarding table and stores the forwarding information in hardware. A slave management service module receives a copy of the first layer 3 forwarding table from the master management service module. When the master management service module fails, the slave management service module initiates construction of a routing table by participating in layer 3 routing protocols. Packet forwarding is not interrupted because forwarding using hardware entries continues. The slave management service module links entries in the newly constructed routing table to those stored in the forwarding table.