Spanning Tree Protocol

Abstract: Shortest path bridging overcomes the limitations of the spanning tree protocol in switched networks. Dominant approaches like Shortest Path Bridges (IEEE 802.1aq) and TRILL (IETF) Rbridges add a link state routing protocol in layer two to compute shortest paths between bridges, but these paths are shared by multiple hosts. Balancing the load at links requires complex equal cost multipath computations. It is simpler instead to find a path between every pair of hosts just-in-time, flooding the standard ARP Request frame through all links, snooping it at bridges with a new port-locking mechanism that associates the source address of frame to the first-arrival port and locks this association for some time, discarding duplicated packets received via other ports just by its source address. It scales to networks of tens of thousands of hosts. Link failures affect only to paths using them. It provides high throughput, low latency and automatic load distribution in campus and data center networks. This paper references the recent work, ”ARP Path: ARP-based Shortest Path Bridges” [1] [2]

Abstract: The invention relates to a system and a method for realizing rapid access control on a wireless local area network. The system comprises an access control hardware switch, a hardware switch response module for detecting a turn on state and a turn off state of the access control hardware switch, a workstation database, and an access control list management module for judging whether an MAC (multi-access control) address of a workstation requesting to be associated is stored in the workstation database, determining whether to construct connection with the workstation according to a judgment result and adding the MAC address of a new workstation into the workstation database when the access control hardware switch is turned off. According to the system and the method for realizing the rapid access control on the wireless local area network, by the adoption of the structure, a user only needs to control the hardware switch and connect an STA (spanning tree algorithm) with an AP to realize the access control on the WLAN, so that the operation difficulty of the user and the ACL (access control list) functional operation steps are greatly reduced, and a wider application range is achieved.

Abstract: The invention provides a method and a device for detecting link failures. The method comprises the following steps: if a BPDU (Bridge Protocol Data Unit) sent by upstream equipment is not received by downstream equipment within first time, sending an STP (Spanning Tree Protocol) Probe message to all ports except a backup port so as to promote network equipment receiving the STP Probe message for the first time to send an STP Ack message when the self bridge ID is identical to the bridge ID of the upstream equipment; when the downstream equipment receives the STP Ack message within second time for the first time and determines that the bridge ID of the downstream equipment is carried in the STP Ack message, if the ID of a port receiving the STP Ack message is different from the ID of a port by which the downstream equipment is connected with the upstream equipment, determining that a link between the downstream equipment and the upstream equipment fails and calculating a distribution tree with the downstream equipment as a tree root. Through the technical scheme, the stability of an MPLS (Multiple Protocol Label Switching) network is effectively improved.

Abstract: In a spanning tree network, topology change notifications are omitted when a port becomes forwarding if the peer port is an Alternate or Backup port in Discarding state. Other features are also provided.