Cabletron Systems 9E423, 9E312 manual Bridge Port Level Fields

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9E312/9E423 Module Bridging

Hello Time

This parameter indicates, in seconds, the length of time the Root Bridge (or bridge attempting to become the Root) waits before resending Configuration BPDUs. The range for this field is 1 to 10 seconds, with a default value of 2 seconds. The Root Bridge sets the Hello Time.

Max Age

This parameter displays the bridge’s BPDU ageing timer. This controls the maximum time a BPDU can be retained by the bridge before it is discarded. During normal operation, each bridge in the network receives a new Configuration BPDU before the timer expires. If the timer expires before a Configuration BPDU is received, it indicates that the former Root is no longer active. The remaining bridges begin Spanning Tree operation to select a new Root. The current Root Bridge on the network sets the Max Age time. The range for this field is 6 to 40 seconds, with a default value of 20 seconds.

Forwarding Delay

This parameter displays the time period which elapses between states while the bridge is moving to the Forwarding state. For example, while moving from a Blocking to a Forwarding state, the port first moves from Blocking to Listening to BPDU activity on the network, remains there for the Forward Delay period, then moves to the Learning State (and remains in it for the Forward Delay period), and finally moves into a Forwarding state. This timer is set by the Root Bridge.

During a topology change, the Forward Delay is also used as the Filtering Database Ageing Time, which ensures that the Filtering Database maintains current topology information.

Hold Time

This parameter displays, in seconds, the minimum time that can elapse between the transmission of Configuration BPDUs through a bridge port. The Hold Time ensures that Configuration BPDUs are not transmitted too frequently through any bridge port. Receiving a BPDU starts the Hold Timer. After the Hold Timer expires, the port transmits its Configuration BPDU to send configuration information to the Root. The Hold Time is a fixed value, as specified by the IEEE 802.1d specification.

Bridge Port Level Fields

The following fields are applicable to each bridge port on the 9E312/9E423

Module.

Priority

If two or more ports on the same bridge are connected to the same LAN segment, they will receive the same Root ID/Root Cost/Bridge ID information in Configuration BPDUs received at each port. In this case, the BPDU’s Port ID information — the transmitting port’s identifier and its manageable Priority component — is used to determine which is the Designated Port for that segment.

Bridge Spanning Tree

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Contents Page Virus Disclaimer Page Restricted Rights Notice Page Contents Index 9E312/9E423 Module BridgingIntroduction Using the 9E312 and 9E423 User’s Guide IntroductionRelated Manuals Software Conventions Common 9E312 and 9E423 Window FieldsUsing Buttons and Menus Getting Help from Cabletron Systems Technical Support Using On-line HelpGetting Help 9E312 and 9E423 Firmware FTPIntroduction 9E312 and 9E423 Firmware 9E312/9E423 Module View Viewing Module Information 9E312/9E423 Module ViewFront Panel Information Connection StatusMenu Structure E312/9E423 Module View Menu Structure Device MenuBridge Menu Utilities MenuHelp Menu 9E312/9E423 Module Port Status Display Bridge Port MenuChassis Manager Window Viewing the Device Type Setting the Device Date and TimeManaging the Module Edit Time Window Using the Find Source Address Feature Enabling and Disabling Bridge PortsSummary Information Find Source Address WindowType Interface Description FieldsIndex DescriptionInterface Performance Statistics/Bar Graphs Raw CountsRate Interface Detail WindowLoad Interface Detail Window Statistics UnicastDiscarded ErrorMulticast Unknown ProtocolPackets Transmitted Testing and Disabling the Current InterfacePackets Received Making Sense of Interface StatisticsUsing the Applications Pull-down menu 9E312/9E423 Module View Summary Information 9E312/9E423 Module Bridging Bridging BasicsAn Overview of Remote Bridge Management More on Transparent BridgingBridge Status Window Bridge Status Window Information Fields Bridge State on InterfaceInterface Speed Interface TypeInterface Address Enabling and Disabling Bridging Bridge StatisticsPerformance Graphs Frames Forwarded Green Errors RedBridge Performance Graph Window Fields Filtered MagentaInterface Statistics Window Configuring the Bridge Performance GraphsInterface Statistics Window Fields AddressBridge Spanning Tree Non-Unicast9E312/9E423 Module Bridging Bridge Priority Configuring the Bridge Spanning Tree WindowBridge Level Fields Root Port Root BridgeRoot Cost ProtocolBridge Port Level Fields Designated Root Path CostDesignated Cost Designated BridgeChanging the Spanning Tree Algorithm Protocol Type Changing Bridge Spanning Tree ParametersChanging Bridge Priority Changing Max Age Time Changing Forwarding Delay TimeChanging Hello Time Changing Path Cost Filtering DatabaseChanging Port Priority 9E312/9E423 Module Bridging Filtering Database Window Number Filtering Database Window FieldsList CapacityReceive Port Configuring the Filtering DatabaseSource Port Port FilteringChanging the Receive Port Altering the Ageing TimeChanging the Type of Entry Changing the Port Filtering Action Adding or Deleting Individual EntriesUsing Port Source Addressing Clearing All Permanent, Static, or Dynamic EntriesSetting the Ageing Time Device Ageing Time WindowDuplex Modes Duplex Modes WindowFull Duplex Duplex Modes Window FieldsInterface Setting the Duplex Mode Index Index-2
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