Abstract: A protocol for discovering a silent device, such as a printer, attached to a mobile port of a switching node. A command is transmitted to the switching node for associating an IP address for the silent device to a particular virtual local area network (VLAN). Entry of the command causes the switching node to start searching for the silent device on the mobile ports. As part of the searching process, an ARP request with the IP address provided in the command is sent to each mobile port of the switching node. When the silent device responds with its MAC address in an ARP reply message, the MAC address is learned in a layer 2 table used for making forwarding decisions of data units received by the switching node. Furthermore, the port where the silent device was discovered, that is, the port receiving the ARP reply message, is associated with the VLAN of the silent device.

Abstract: A method is described herein for configuring a computer network managed by the IEEE Std 802.1s™-2002 MSTP standard or any other equivalent standard such as IEEE Std 802.1Q™-2003 in a fully- or semi-automatic manner such that: (1) if at all possible and in the case of a failure in the MSTP-based computer network affecting a Multiple Spanning Tree Instance (MSTI), MSTP reestablishes connectivity in that MSTI by preferably activating links whose activation ensures that the connectivity within a Virtual Local Area Network (VLAN) mapped onto and associated with that MSTI is not lost; and (2) a VLAN is mapped onto a MSTI whose active topology covers the topology of this VLAN, this being ensured by setting up that MSTI depending on the desired VLAN topology.

Abstract: Customer virtual local area networks (C-VLANs) connecting multiple LAN segments are set up through a provider network (12). Provider edge bridges (PEs) are coupled to customer edge bridges (CEs) to provide a transparent link between LAN segments. To determine whether a backdoor link is used in the C-VLAN topology, PEs monitor MAC address from a predetermined time after a TCN is received to determine if there are contradictory addresses or new addresses relative to the existing MAC address tables (or forwarding databases) that are indicative of a backdoor link. If so, an unlearning message is sent to bridges in the provider domain. In another embodiment, CEs set a snoop bit to indicate which TCNs must be snooped.