Dsap Values | EXP Computer S200 specs

Bridge Filtering

DSAP Values	The DSAP is a 1-byte ID found in the LLC field (see Figure 37). You set this value
	in the Protocol Value parameter of the Protocol Filter Table. Examples of DSAPs
	include:
	•	IBM (04, 08,...)
	•	Banyan Vines (BC)
	•	Novell IPX (E0)
	•	IBM NetBIOS (F0)

LLC Field

DSAP SSAP

Control

LLC Info

Figure 37. Protocol ID DSAP Located in LLC Field

SNAP Protocol ID The SNAP is five bytes and is also found in the LLC field. The first three bytes are

OUI and the last two bytes are the Protocol ID (Figure 38).

LLC Field

DSAP SSAP

Control

5 Bytes

AA

AA

03

OUI	Type
00 00 00	2 Bytes

AA= Indicates SNAP Format

03 = Unnumbered Information

OUI	=	Organizationally Unique Identifier
Type	=	2-Byte Protocol ID

Figure 38. SNAP Protocol ID

The SNAP format is used to identify Ethernet and pre-IEEE 802 protocol IDs that do not fit the 1-byte ID.

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Bridging

Image 78

EXP Computer S200 manual Dsap Values

Contents

3Com Corporation Restricted Rights Notification for U.S. Government Users Restricted Rights Legend Proprietary Material Page Functionality SolutionsOverview Multiple LANs No Local Bridging TranslationalBridging Transparent This Manual Topic This Notice Topic Introduction Bridging Features and CapabilitiesSwitches Bridging Primer Ethernet LAN Operation ExampleEthernet Bridge WAN application, but you can also bridge across an X.25 WAN Mixed LAN Bridging MAC Addressing Termination LLC2 Local TerminationLLC2 Local LT Example Autolearn for Local Termination Mac Address NetBIOS NameFiltering Filtering What Is It? Automatic Manual Spanning Tree Support Spanning Tree Protocol Dual Ethernet LANs Basic Remote Bridging Examples Across a WANWAN or Permanent Virtual Circuit PVC for Frame Relay Example of Bridges in an SVC Arrangement LAN Interface BridgeConnections Support Bridging Setting Up WAN Operation for Bridging Interface Connections Between WAN and LAN Setting Up WAN Operation for Bridging Configure These parameters make up the Bridge Parameter Record Bridge ParametersParameters Maximum Number of Bridge Links AUTO, MAN Bad Hello TimeoutStpe Control MAN Learn Only Period used for Ethernet only Aging Period used for Ethernet onlyBridge WAN Data Priority used for Ethernet only Bridged Protocols Bridge links as links to the networks attached to it Parameters control the characteristics of this connectionBridge Link Parameters Bridge Link BridgeType These parameters make up the Bridge Link RecordEntry Number SR, TB, Bothsrandtb MAC Address Filter Action Hop Count LimitLargest Frame Size NONE, PASS, Block Netbios Name Filter Action Protocol Filter ActionStpe Link State Normal Link ModeNORMAL,RFC1294, Trans Virtual Ring Number LAN Connection LAN Connection TableOver the WAN Table Parameters Rout LAN Forwarder TypeROUT, BRID, Brout LAN Connection Type Autocall Mnemonic Encapsulation TypeCodex Lcon Queue Limit OFF Billing RecordsOFF, on Traffic Priority Overview Where bridging is done remotely across a WANLimiting Bridge Frame Sizes Transmission times for large frames become significant Maximum frame size Standard FrameSizes Max Frame Size Line Speed Range kbps Configuring Translational Bridging Translational Bridging Example Bridge Frame Handling Node for SRB Configuring Source Route Bridging OperationConfiguring Individual Bridge Bridging LAN for a Source Route Bridging operation Connecting a Station to a Server in Source Route BridgingProcedure Located on remote LAN CCC Figure Server’s Destination MAC Address Not on LAN AAA LAN Bridge Link WAN Adapter Transmits Each are Frame Across the WAN Server Responds with Specifically Routed Test Frame Step Action Result/Description Then Transparent Bridging for Ethernet LANs LearningForwarder Statistics LAN link WAN link Link errorForwarder Example Filtering Hardware Accelerator LAN/WAN HandlersHardware Accelerator Functions Forwarder Functions Forwarder Initialization Learn Only Period Aging Forwarder Database and Spanning Tree Using Filters List, the frame is dropped Multicast LinkFrame is dropped Control menu located in the Main menu Local MAC Address Transparent Bridge Configuration ParametersTB Forwarding Bridge Link Number What is It? How Filtering is Used Bridge Filtering MAC Address Filtering Parameter Action Parameter Parameter Action Value MAC Filtering Process Mac Filtering Process Incoming and Outgoing Frames Example of a Frame Passing on a Bridge Link MAC Address Filtering Examples How To Configure ExampleConfiguring the Bridge Link Record First Example Configuring the MAC Address Filter Table Why it is Important Identifying Address Links for MAC AddressingAddress Links Series Switch Support MAC Wildcard FilteringFiltering works Configuring the MAC Address Filter Table Broadcast frames in the LAN networkCategories PASS, BLOCK, PASSLIST, Blocklist These parameters make up the MAC Address Filter TableIncoming Source Address Link Action Pass Outgoing Source Address Link Action Incoming Destination Address Link Action Outgoing Destination Address Link Action List of Links Protocol Filtering Protocol Filter These parameters make up the Protocol Filter Table Record Protocol OUI/IP hex value Protocol TypeProtocol SAP hex value Protocol Value Incoming Protocol Link Action Outgoing Protocol Link Action Dsap Values Parameter Actions NetBIOS Name Filtering Broadcasts to and from the SVR* name patternTransparent Bridging Domain With Checking NetBIOSForcing a Local Filters NetBIOS Name Filtering Configuring NetBIOS Name FilteringHow to Configure Step Action Entry Number 1 appears Select Configure ConfigureStep Action Result Bridge Bridge Link Bridge -NetBIOS Name Filter Configure NetBIOSNetBIOS Name Filter Table Name Filter Table Typical Filtering String TypeAscii Incoming NetBIOS Name Link Action Incoming NetBIOS Name List of Links Outgoing NetBIOS Name Link Action Outgoing NetBIOS Name List of LInks Each bridge link NetBIOS Name Filtering StatisticsNetBIOS broadcasts filtered on the link Check Detailed All of the following are true NetBIOS Packet FormatsIBM NetBIOS Formats When to Use NetBIOS Name Filtering Either one of the following is true Spanning Tree Configuration Stpe Control= Auto Stpe Control = Manual MenuSpanning Tree Protocol Entity Stpe Tree Bridge Links Spanning Tree Protocol Entity Stpe Stpe Parameter Setting Considerations Example of aBridge Network Setting the Root Bridge Spanning Tree Bridge ID equals Bridge Priority Value in hex + MAC AddressDetermining Root Links Designated Links Type of Network Speed Stpe Path Cost Expected Number ConsiderNature SVCs Two Bridge Links Between B3 and B4 Spanning Tree Protocol Entity Stpe Hello Timer Spanning Tree TimersTimer Parameters Max Age Other Considerations Bridge Forward Delay Timer Message Events in Network Spanning Tree Protocol Entity Stpe Aging Timer Bridges can adjust to the changeLocation and forwards packets to it properly Preventing session timeouts in a Bridging application LLC2 Local Termination Before Local Well as network delaysTerminal session, causing After Local Supported TopologiesImproper LT Proper LT configuration LLC Protocol LLC Frame Description LLC2 Frame DescriptionType Name Description Local Termination spoofs Local Termination does not spoof Bridging 105 Configuring Local Termination Local Termination Boot Type LLC LT Station StepStation Table Entry Number Local SAP WAN Parameters T1Reply TimerT2 Rx Ack Timer LLC Profile Name N3 ACK Delay Count Boot Type LLC LT WAN ParametersTi Inactivity Timer N2 Retry Count LCC LT WAN Data Priority Configuration Entry NumberTx Window Size HIGH, MEDIUM, LOW T1 Reply Timer 112 Bridging Deleting LT Configuration Records 27x switch, as shown in Figure Mixed LAN OperationMixed LAN Environment Limitations Bridge Link Parameters from Select Configure BridgeBridge Link Parameters menu CTP Main menu, to activate Bridge link Bothsrandtb System powerup Dual LAN Ethernet Dual Ethernet LAN RoutingSupported Cmem For Details on Parameters LAN Server Subsystem Alarms Record Configuring the LSS RecordExample of LCC Virtual Port’s MAC Address Virtual Bridge ID ENABLE, DisableDisable Path Trace Control Bridge Statistics Statistics Menu screen Status report Spanning Tree StatisticsStpe Status Term Description Are Disabled The Stpe is disabled. If Stpe ControlState Parameter is MAN Detailed Bridge Link Statistics Detailed Bridge Link Statistics First Screen Terms RIF Summary Bridge Link Filter SummaryLink Filter Description Bridging 131 Stats Descriptions Transparent Bridge Forwarding Table StatisticsStats Example Shown in Figure Bridging 133 Transparent Bridge Detailed Bridge Link Statistics Terms-Transparent Bridge Second FF-FF-FF-FF-FF-FF Frame Totals This is a count of the number of framesReceived/transmitted of all types on this link LAN Connection Statistics Statistics MenuDetailed LAN Connection Statistics Detailed LAN Connection Statistics Second Connection and explains why the call was cleared Explains why the last call was clearedLast clear diagnostic code This is the diagnostic code SVCs. The possible states are Blank for PVCs blank Bridging 139 Example of LAN shows the LAN Connection Summary Statistics Connection Summary Statistics SAP LLC2 LT Session Summary StatisticsHeading Description Remote MAC Addr Heading LLC2 LT Detailed Session Statistics Session Statistics Last Statistics Last time statistics were reset Reset Routing information field used in all frames transmittedField, ring number, and bridge number information Heading Description Local Station Session Summary Heading Description Remote Spoofer Session Summary Reset Statistics 148 Bridging Technical Support Access by Digital Modem Access by Analog Modem3ComFacts Automated Fax Service Country Data Rate Telephone Number Support from 3ComCountry Telephone Number Country Telephone Number Fax Number Index Numerics LAN OUI URL A-1 Index-5