Asante Technologies 35160 user manual Spanning Tree Protocol, Port Vlan ID, How It Works

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7.1.3 Port VLAN ID

To allow untagged packets to participate in a VLAN, a Port VLAN ID (PVID) must be assigned in the relevant port(s).

Each port on the switch has a default PVID of 1 (the default VLAN) and will receive both tagged and untagged frames. The manager may configure the PVID of any desired port (the range is 1 to 4094). For ports that have been configured to receive only tagged frames, the PVID is meaningless. If a port is configured to receive only tagged frames, then any untagged frame received will be dropped. Tagged frames that are received will be forwarded to the VLAN represented by the VID in the tag header of the frame.

7.2 Spanning Tree Protocol

The Spanning Tree Protocol (STP) is part of the IEEE 802.1D standard. It provides for a redundant network without the redundant traffic through closed paths. For example, in a network without spanning tree protocol, the same message will be broadcast through multiple paths, which may start an unending packet-passing cycle. This in turn causes a great amount of extra network traffic, leading to network downtime. The STP reduces a network like this, with multiple, redundant connections, to one in which all points are connected, but where there is only one path between any two points (the connections span the entire network, and the paths are branched, like a tree).

7.2.1 How It Works

All of the bridges (a switch is a complex bridge) on the network communicate with each other using special packets of data called Bridge Protocol Data Units (BPDUs). The information exchanged in the BPDUs allows the bridges on the network to do the following:

Elect a single bridge to be the root bridge

Calculate the shortest path from each bridge to the root bridge

Select a designated bridge on each segment, which lies closest to the root and forwards all traffic to it

Select a port on each bridge to forward traffic to the root

Select the ports on each bridge that forward traffic, and place the redundant ports in blocking states

7.2.2 Spanning Tree Parameters

The operation of the spanning tree algorithm is governed by several parameters. The manager should attempt to set these parameters only if they have experience with the 802.1D specification. To set the parameters listed below, access the Spanning Tree/Bridge Settings screen (console or telnet), or the Spanning Tree/Bridge Settings page (in the Web interface).

Bridge Priority

Setting the Bridge Priority to a low value will increase the likelihood that the current bridge will become the root bridge. If the current bridge is located physically near the center of the network, decrease the Bridge Priority from its default value of 32768 to make it become the root bridge. If the current bridge is near the edge of the network, it is best to leave the value of the Bridge Priority at its default setting.

Hello Time

This is the time period between BPDUs transmitted by each bridge. The default setting is 2 seconds.

Maximum Age

Each bridge should receive regular configuration BPDUs from the direction of the root bridge. If the maximum age timer expires before the bridge receives another BPDU, it assumes that a change in the topology has occurred, and it begins recalculating the spanning tree. The default setting for Maximum Age is 20 seconds.

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Contents IntraCore 35160 Series Quick Start Guide IntraCore 35160 Series Layer 2 Gigabit Switches User’s ManualTable of Contents Page Introduction FeaturesLEDs SwitchCore CXE2010Package Contents 2 IC35160-G 1 IC35160-TFront and Back Panel Descriptions Management and ConfigurationSnmp Management Console InterfaceWeb-Based Interface Installation Overview Hardware Installation and SetupSafety Overview Recommended Installation ToolsPower Requirements Installation into an Equipment RackEnvironmental Requirements Cooling and AirflowGbic Interfaces Installing a GbicConnecting Power Installing the Optional Emergency Power SupplyRemoving a Gbic Gbic Care and Handling1 10/100/1000BaseT Ports Cabling Procedures Connecting to the NetworkConnecting to a Console SetupGigabit Ethernet Ports Cabling Procedures Connecting Via Telnet Connecting Via the Web BrowserIP Assignment Changing the PasswordSimple Network Management Protocol Snmp Accessing a Submenu ConfigurationLogging Exiting a SubmenuGeneral Information Configuration MenuChanging System Administration Info Administration ConfigurationChanging System IP Information System IP ConfigurationPort Configuration Page Enabling or Disabling a Port Advanced Port ConfigurationSetting Port Default Priority Setting Port Class of ServiceSetting Port Maximum Packet Length Enabling or Disabling 802.3x Flow ControlGlobal Port Configuration Unicast Forwarding Database ConfigurationDisplaying the Forwarding Database Security Management Setting the MAC Address Age-Out TimeVlan Management Searching for a MAC AddressChanging Community Strings Protocol ConfigurationSnmp Configuration Adding or Updating a Trap Receiver Enabling Authentication TrapsDeleting a Trap Receiver Spanning Tree Protocol STP ConfigurationEnabling and Disabling STP Spanning Tree Port ConfigurationSetting Port Priority and Path Cost Trunk Group Configuration Assigning Packets to Priority Queues QoS Priority Queue ManagementDefining the Priority List Example Setting SSH/Telnet UI Time-out User Interface ConfigurationSetting Console UI Time-out Period Enabling or Disabling SSH and Telnet Change PasswordAdding or Deleting an Access Host Enabling or Disabling the Web Server Access ControlSystem Utilities Adding or Deleting a Monitor Port Port MirroringEnabling or Disabling System Port Mirroring System Clock System ResetResetting the Switch System Log Scheduling a System ResetClearing the System Log Bootstrap ConfigurationTftp File Transfers Ping Utility StatisticsRmon Management Advanced ManagementSnmp and Rmon Management Enabling and Disabling Duplicated IP Detection Duplicated IP Detection and TrapEnabling and Disabling Duplicated IP Trap Viewing a List of Duplicated IP AddressesEnabling and Disabling Station Movement Trap Configuring Port SecurityConfiguring Port Lock and Intruder Lock Configuring Port New Node Detection TrapConfiguring Security Level 2 or Level Port-based Network Access ControlSetting the Intruder Trap Resetting Security to DefaultsPage Name Description Port Control SettingsSetting Timers Server Port Setting Radius ParametersRadius Server IP Vlan Management Vlan Specifications for the IntraCore 35160 SeriesOther Vlan Features of the switch Creating a Vlan Configuring Static Vlan GroupsAdvanced Static Vlan Configuration Setting the Port Vlan ID Configuring Vlan Port AttributesConfiguring Port Receive Frame Type Adding and Deleting VLANs from the PortDisplaying a Summary of Vlan Groups Setting Port TypeIP Multicast Traffic Management Resetting Vlan Configuration to DefaultsDisplaying a Vlan Port Summary Multicast AddressesEnabling and Disabling Igmp Snooping Configuring IP Multicast Traffic ManagementIgmp Snooping Displaying a Summary of Group Addresses Advanced Igmp ConfigurationAdding Ports to the Selected Address IP Multicast Forwarding Database ConfigurationInserting a Multicast Group Address Removing a Multicast Group AddressWeb-Based Management Accessing with a Web BrowserManagement Buttons Front Panel ButtonGenl Info General Information Button Port Config Port Configuration Button Span Tree Spanning Tree Button Addr Address Table Button Snmp ButtonVlan Group Create Vlan ConfigurationVlan Button Set Port Type Port ConfigurationPort Vlan ID Pvid Acceptable Frame TypeSecurity Button Trunking ButtonPort Ingress Filtering Tag/Untag Port Egress TypePage Snmp Protocol Snmp ManagementSnmp Management Operations Name Space Path Community Name and Security MIB Tree MIB Groups Supported VLANs Switching ConceptsPort-Based VLANs Vlan ID and Tagged FramesPort Vlan ID Spanning Tree ProtocolHow It Works Spanning Tree ParametersFull Duplex Spanning Tree Port ConfigurationFull Duplex, Flow Control, and Auto-negotiation Auto-Negotiation Flow ControlProblem Possible Solutions Appendix A. TroubleshootingPhysical Characteristics Appendix B. Features and SpecificationsSpecifications Standards Compliance Technical Support and WarrantyEnvironmental Range IntraCare Warranty Statement Appendix C. FCC Compliance and Warranty StatementsFCC Compliance Statement Important Safety Instructions Page Appendix D. Console Port Pin Outs Pin Number Signal NameAppendix E. Online Warranty Registration Bootstrap Configuration Appendix F. BootP ConfigurationImage Banks Loading Software LocallyLoading Software Remotely BOOTP-TFTP