HP J3178A manual Spanning Tree Operation, Spanning Tree Protocol STP

Page 103

D

Spanning Tree Operation

	Spanning Tree Protocol (STP)
	The Switch 208/224 Management Module uses the IEEE 802.1d Spanning Tree
	Protocol (STP) to ensure that only one path at a time is active between any
	two nodes on the network. In networks where there is more than one physical
	path between any two nodes, STP ensures a single active path between them
	by blocking all redundant paths.
	STP is necessary in such networks because having more than one path
	between a pair of nodes causes loops in the network, which can result in a
	switch detecting the same node on more than one port. This results in
	duplication of messages, leading to a “broadcast storm” that can bring down
	the network.

N o t e	The default STP setting in the switch is “Off”. If you are using the switch to
	provide redundant network paths, you should reconfigure the Spanning Tree
	Protocol to “On”. Refer to “Spanning Tree Configuration” in chapter 4, “Con-
	figuring the Switch From the Console” for procedures on enabling STP.
	While allowing only one active path through a network at any time, STP retains

	any redundant physical path to serve as a backup (blocked) path in case the
	existing active path fails. Thus, if an active path fails, STP automatically
	activates (unblocks) an available backup to serve as the new active path for
	as long as the original active path is down. In the event of a topology change
	such as a switch, bridge, or data link failure, STP develops a new spanning
	tree that may result in changing some switch ports from the blocking state to
	the forwarding state.
	For example, see the illustration on the next page.

Spanning Tree Operation

D-1

Image 103

Contents HP AdvanceStack Switch 208/224 Management Module Page Installation and Reference Guide HP AdvanceStack Switch 208/224 Management ModulePublication Number World Wide Web HP Customer Support ServicesHow to get the latest software/agent firmware HP FTP Library ServiceAdditional HP Support Services HP First Fax Retrieval ServiceLocation Phone Number Contents Monitoring Switch Operation From the Console Spanning Tree Operation Viii Installing the Management Module Installing the Management ModuleIncluded Parts Installation StepsAnti-Static Precautions Installing Installing the Management ModuleRemove the cover plate Removing the Module At Power OnOverview Management Module DescriptionManagement Module Description Management Module DescriptionModule Features Page T e Switch ConsoleSwitch Console Connecting a Console to the SwitchConnecting a PC or Terminal to the Console RS-232 Port Remote Console Connection Using a Modem and a PC Modem Cable Pin-Out Starting and Ending a Console Session How To Start a Console SessionMain Menu How To End a Console SessionMain Menu Features Actions line Screen Structure and NavigationTaskActions How To Navigate in the ConsoleLevel Actions Permitted Using Password SecurityTo set Manager and Operator passwords Capabilities, also set an Operator passwordTo Recover from a Lost Manager Password To Delete Password ProtectionSelect Delete Password Protection To Recover from a Lost Operator PasswordReboot Switch Option in the Main Menu Switch Console Rebooting the SwitchExample of a Configuration Change Requiring a Reboot Listing of Commands Available under Advanced Commands Advanced CommandsHow To Use the Advanced Commands How To Exit from the command promptPage Configuring the Switch From the Console Configuring the Switch From the ConsoleDefault values are shown in brackets ConfiguringHow To Access the Switch Configuration Configurable FeaturesConfiguring Configuring the Switch From the Console System ConfigurationExample of the Port Configuration Screen Port ConfigurationIPX Service Configuring the Switch From the Console Internet IP Service To manually configure the switch for IP Using BootpTo configure the switch for Bootp Bootp Operation Where Snmp Communities How To Configure the Switch for Snmp CommunitiesSnmp Communities Add or Edit Screen Trap Receivers 10. The Serial Link Configuration Screen Default Values Serial Link Configuration11. The Console Configuration Screen Default Values Console ConfigurationPress the Space bar to select Yes . This enables STP Spanning Tree Configuration12. Example of the STP Configuration Screen Network Monitoring Port 13. The Default Network Monitoring Configuration Screen14. Example of Selecting a Monitoring Port Saving Configurations Page Main Menu Data Type Purpose Monitoring Switch Operation From the ConsoleStatus and Counters Menu Monitoring Switch Operation From the ConsoleMonitoring Example of Switch Information Switch InformationExample of Port Status Port StatusExample of Port Counters Port CountersExample of Port Counters Show Details Port Counters Show DetailsExample of the Address Table Address TableTo use the port address table Port Address TableExample of a Port Address Table for a Specific Port Example of Spanning Tree Information Spanning Tree STP InformationOperation and read the Ieee 802.1d standards document 10. Example of STP Port InformationSeverity Date Time System Module Event LogKey Action Event Log Control KeysSwitch Console Using Snmp To Monitor and Manage the Switch HP Proprietary MIBs include Snmp Management FeaturesSnmp Configuration Process Rmon Advanced Management Rmon Ease SupportTroubleshooting Checking the Module LEDs TroubleshootingStatus Description Problem Solution Problem/Solution TableDiagnostic Tests IP Configuration ErrorsTesting the Switch and Management Module Testing the Switch’s Ports and the Links Troubleshooting Resetting the Switch T e Clearing Passwords on the Switch ConsoleHP BBS Page Environmental SpecificationsSupported Mibs SpecificationsVcci Class 1 For Japan Only Regulatory StatementsPage At the switch Modem ConfigurationEnd At the user end Modem ConfigurationDownloading an Operating System File TransfersFile Transfers Using Tftp To Download the OS FileWriting System Software to FLASH, Back Soon Using the Switch-to-Switch Download Using the SNMP-Based HP Download ManagerJumping to console code Using the Zmodem to Download the OS FileFigure C-3. Example of Message for Download Failure Troubleshooting Tftp DownloadsFile to be copied Command Function Transferring Switch ConfigurationsConfiguration Zput config remotefile overwrite dos/unix Spanning Tree Protocol STP Spanning Tree OperationSpanning Tree Operation Clear button description … IndexDefaultconfig IP/IPX MIB STP Tftp Page 5966-5228