3Com 10002211 manual Modifying the Default Vlan, How CoreBuilder System Makes Flooding Decisions

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About VLANs

C-5

Modifying the Default VLAN

New switch ports can dynamically appear in the CoreBuilder system if you insert a new switching module (FESM, FSM).

When a new switch port that is not part of a default VLAN appears in the system at initialization, the system software adds that switch port to the ﬁrst default VLAN deﬁned in the system.

CoreBuilder VLANs also allow you to modify the initial default VLAN to form two or more subsets of switch ports. If you remove the default VLAN and no other VLANs are deﬁned for the system, no ﬂooding of trafﬁc can occur.

How the

CoreBuilder System

Makes Flooding

Decisions

Protocol-sensitive VLANs directly affect how the CoreBuilder system performs ﬂooding. Without protocol-sensitive VLANs, the ﬂooding process is to forward data to all switch ports in the system. With protocol-sensitive VLANs, the ﬂooding process follows this model:

■As a frame is received that needs to be ﬂooded, it is decoded to determine its protocol type.

■If a VLAN exists for that protocol in the CoreBuilder system and the frame’s source port is a member of the VLAN, the frame is ﬂooded according to the group of ports assigned to that VLAN.

■If a VLAN exists for that protocol in the CoreBuilder system but the frame’s source port is not a member of the VLAN deﬁnition, then the frame is ﬂooded according to the default VLAN assigned to that port.

■If the protocol type of the received frame has no VLAN deﬁned for it in the system, the frame is ﬂooded to the default VLAN for the receive port.

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Contents Corebuilder CoreBuilder Extended Switching Software Revision October 17United States Government Legends Contents IP Multicast Routing Vlans on the Corebuilder System 3COM Corporation Limited Warranty Overview CoreBuilder 6000 Extended Switching software from 3ComDated May 30 Corebuilder 6000 Extended Switching Software Revision Updating Your System Software Remove diskette #2 using the following command Remove diskette #1 using the following commandRemove diskette #3 using the following command Remove diskette #5 using the following command Remove diskette #4 using the following commandFollowing ﬁles are now in your /usr/lp6000R directory Software on Loading SystemLMM+ \3com\lp6000R\image\lp6000R Documentation UserRevision 8.2.3? What’s New atCorrections implemented at this release To deﬁne an IP interface AxFDDI axFDDI group AxFDDIHistory axFDDI group Enter the number of the Vlan whose interface you are deﬁningSystem prompts you for slot numbers To enable Spanning Tree transitions, enterTo disable Spanning Tree transitions, enter Displaying Bridge InformationSample display of bridge port information Corrections that are implemented at this release Revision 8.2.0?What’s New at Revision 8.2.0? System displays this message You receive the prompt to select each port’s duplex modeDefault To select the default all, press Return FTP Packet Filter Program Transfers via Snmp ﬁrst telnet session is disconnected and the system displays Sample screen showing the display after the changes What’s New at Revision 8.2.0? This message is immediately overwritten with Power supply +5-volt input has failedPower supply +12-volt input has failed Power supply +5-volt input is restoredSystem Issues System nvdata reset System Issues New Imports section now looks like this Known ProblemsReceived ftpCommand Quit not completed errno Corebuilder 6000 Extended Switching Software Revision Snmp MIB Files Support for IP routing on the Fddi Switching Module FSM Configurable Source Route hop count limit Efsm LpBridgePortAddressLearnedEvent Corebuilder 6000 Extended Switching Software Revision Following parameters IP Multicast RoutingDisabling Dvmrp EnablingDisabling Igmp Multicast Administering IPInterfaces Example multicast interface conﬁguration for the slot Multicast interfaceEnabling Multicast Interfaces Disabling Multicast InterfacesAddress of the remote multicast router AdministeringMulticast Tunnels ExampleEnter the Time To Live TTL threshold of the tunnel Associate a multicast tunnelEnter the IP address of the destination multicast router Enter the Dvmrp metric value of the tunnelDisplaying Routes Table A-1describes the ﬁelds in the route display Following display shows all available multicast routesMulticast Cache DisplayingFollowing display shows the multicast cache conﬁguration Table A-2describes the ﬁelds in the CacheDisplay Remote Monitoring Rmon B Technology Implementation CoreBuilderSegment being monitored Table B-3 Supported Ethernet and Fddi Frame Size Buckets Rmon Groups Example of an Alarm Threshold Setting Alarm ThresholdsRmon Groups 3Com Transcend Rmon Agents Management Information Base MIB Figure B-3 Example of an Rmon MIB Counter Object Locations About VLANsCoreBuilder system, VLANs allow you to Create ﬁrewallsAppendix C Vlans on the Corebuilder System Protocol Suite SNA Layer 3 Addressing InformationHow CoreBuilder System Makes Flooding Decisions Modifying the Default VlanVlan Exception Flooding Overlapped IP VLANs Routing Between VLANs Displaying Vlan Information Administering VlansExample of a summary display for several VLANs Table D-1describes these statistics As an Efsm or a TMM Deﬁning VlanInformation for a Traditional BridgeEnter the subnetwork mask Information for An HSI Switch EngineDeﬁning Vlan Follow these steps to create a Vlan deﬁnition Enter the IP subnet address Enter the subnetwork mask Bridge vlan modify Bridge vlan remove Technical Support Access by Analog Modem Type go threecom Regional Sales Office Telephone Number 3Com Corporation Returning Products for Repair Page 3Com Corporation Limited Warranty Limitation of Liability