Cabletron Systems CSX400, CSX200 manual About Transparent Bridging, About Source Route Bridging

Page 48

Bridging

About Transparent Bridging

Transparent bridges are most common in Ethernet networks. Individual Transparent bridges monitor packet trafÞc on attached network segments to learn where end stations reside in relation to each segment by mapping the Source Address of each received frame to the port (and segment) it was detected on. This information gets stored in the bridgeÕs Filtering Database.

When in the Forwarding state, the bridge compares a packetÕs destination address to the information in the Filtering Database to determine if the packet should be forwarded to another network segment or Þltered (i.e., not forwarded). A bridge Þlters a packet if it determines that the packetÕs destination address exists on the same side of the bridge as the source address.

If two or more bridges are connected to the same Ethernet LAN segmentÑplaced in parallelÑonly a single bridge must be allowed to forward data frames onto that segment. If two or more bridges were forwarding data frames onto the same Ethernet segment, the network would soon be ßooded.

With a data loop in the topology, bridges would erroneously associate a single source address with multiple bridge ports, and keep proliferating data by forwarding packets in response to the ever-changing (but incorrect) information stored in their Filtering Database.

To avoid such data storms, Transparent bridges communicate with one another on the network by exchanging Bridge Protocol Data Units (BPDUs) to determine the network topology and collectively implement a Spanning Tree Algorithm (STA) that selects a controlling bridge for each LAN segment; this ensures that only a single data route exists between any two end stations and that topology information remains current.

About Source Route Bridging

Source Routing is typically used to connect two or more Token Ring network segments. Source Route bridges differ from Transparent bridges in that they do not build and then use a physical address database to make forwarding decisions. Instead, the source end station transmits packets with a header that contains routing information (added by bridges in the network topology during a route discovery process between end stations); once a route has been determined, a Source Route bridge simply reads the header of a source routed packet to determine whether it is a participant in routing the packet.

In Source Routing, sending and receiving devices employ broadcast packetsÑknown as explorer packetsÑto determine the most efÞcient route for a message to travel. Generally, before a station sends a message, it will Þrst send a test packet to all stations on the same ring; if the sending station receives a response to this packet, it assumes that the destination station is on the same ring and therefore it will not include routing information in frames sent to that station in the future. Any further packets issued between stations will appear to be transparent-style frames without embedded routing information.

4-2

Bridging Basics

Page 47 Page 49
Image 48
Page 47 Page 49
Contents CSX200 and CSX400 User’s Guide Page Virus Disclaimer Page Restricted Rights Notice Page Contents Chapter Bridging Vii Index Token Ring Physical Status FieldsIntroduction Using the CSX 200 and CSX400 User’s Guide HSIM-W6 and HSIM-W84Related Manuals Software Conventions Common Window FieldsDevice Name Using the Mouse IP AddressLocation MAC AddressUsing Window Buttons Using On-line Help Getting HelpGetting Help from the Cabletron Systems Global Call Center CSX200 and CSX400 Firmware CSX200 and 400 Chassis View Viewing Chassis Information CSX200 and CSX400 Chassis View WindowsFront Panel Information Menu Structure TimeDate Device Menu Port Status MenuUtilities Menu Help MenuPort Menus CSX200/400 Port Status Displays Selecting a Port Status ViewStatus Load Chassis Manager Window Port Status Color CodesViewing Hardware Types Device TypeManaging the Device Viewing the Port DescriptionUsing the Find Source Address Feature Viewing I/F Summary InformationIndex DescriptionPhysical Status Logical StatusInterface Performance Statistics/Bar Graphs Raw CountsRate Viewing Interface Detail Detail Interface StatisticsError AddressUnicast Non-UnicastEnabling and Disabling Ports Packets Transmitted Transmit onlyMaking Sense of Detail Statistics CSX200 and 400 Chassis View CSX200 and 400 Chassis View Managing the Device CSX200 and CSX400 WAN Configuration About the CSX200 SeriesAbout the CSX400 WAN RedundancyCSX WPIMs WPIM-DDSEIA-RS449 WAN Logical View WAN Logical View WindowChanging WAN Logical Settings WAN Logical View Window FieldsCSX200 and CSX400 WAN Configuration CSX200 and CSX400 WAN Configuration WAN Logical View Bridging Bridging BasicsAbout Transparent Bridging About Source Route BridgingBridging About Source Route-Transparent Bridges About Source Route-Translational BridgesBridging Viewing and Managing Bridging Interfaces Bridging Bridge Status Window Bridge Status Window Information FieldsUp Time Bridge State on InterfaceAccessing Other Options from the Bridge Status Window Interface TypeBridge Address Bridging Bridging Bridging Enabling and Disabling Bridging Enabling and Disabling Individual InterfacesFrom the Bridge Status window Enabling and Disabling All Installed Interfaces Bridge StatisticsPerformance Graphs From the Chassis View windowFrom the Bridge Status window Bridge Performance Graph Window Fields Frames Forwarded GreenFiltered Magenta Errors Red Xmitted BlueConfiguring the Bridge Performance Graphs Bridge Detail Breakdown WindowFrames Forwarded FilteredXmitted Bridge Port Detail Breakdown WindowForwarded to Forwarded fromInterface Statistics Window I/F Statistics WindowStatistics Window Fields Csmacd Statistics Window Unknown ProtocolPackets Received Transmit Queue SizeReceive Errors AlignmentTransmission Errors Collision Errors PPP Link Statistics WindowErrors Bad AddressesBad Controls Packets Too LongStatistics Dot5 Errors Statistics Window Line Errors Burst ErrorsInternal Errors Congestion ErrorsToken Errors Soft ErrorsSource Route Statistics Bridge Source Routing Window Fields Received FramesSpecif. Routed All Paths ExplTransmitted Frames DiscardsBridge Spanning Tree Hop Cnt. ExceededConfiguring the Bridge Spanning Tree Window Bridge Level FieldsBridge Priority Root Bridge Root CostRoot Port Bridge Port Level Fields Path Cost Designated CostDesignated Root Designated BridgeChanging Bridge Spanning Tree Parameters Changing Bridge PriorityChanging the Spanning Tree Algorithm Protocol Type Changing Forwarding Delay Time Changing Hello TimeChanging Max Age Time Filtering Database Changing Port PriorityChanging Path Cost Bridging From the Bridge Status window Filtering Database Window Fields ListNumber CapacityConfiguring the Filtering Database Aging TimeSource Port Receive PortAltering the Aging Time Changing the Type of EntryChanging the Receive Port Changing the Port Filtering ActionAdding or Deleting Individual Entries Ethernet and Token Ring Special Filter Databases Clearing All Permanent, Static, or Dynamic EntriesEthernet Special Filter Database Window Token Ring Special Filter Database Window 13. Ethernet Special Filter Database WindowEnable Special Filter Database Window FieldsFile Destination AddressDefining and Editing Filters in the Special Database This Setting the Port Filtering Action Changing the Receive PortsChanging the Port Filtering Action Enabling and Disabling a Filter Saving a Set of Filters to a FileClearing the Port Filtering Action Source Route Configuration Information on Source Routing 16. Source Route ConÞguration WindowSource Route Configuration Window Source Route Configuration FieldsSubnet Mask Local SegmentTarget Segment Hop Count LimitSpanning Tree Expl Bridge NumberSpanning Tree Mode Using the Find Source Address Feature Making and Setting ChangesPort Source Addresses Window Setting the Aging Time Duplex Modes Duplex Modes Window Duplex Modes Window FieldsInterface Setting the Duplex Mode Full DuplexStandard Mode Ethernet Port Configuration WindowFast Ethernet Port Configuration Current Operational Mode Port TypeLink State Desired Operational Mode Advertised AbilitiesRemote Capabilities Setting the Desired Operational Mode for the FE-100TX Setting the Desired Operational Mode for the FE-100FXSonet Port Configuration SONET/SDH ConfigurationSonet SONET/SDH Statistics Window Bridging 24. The SONET/SDH Statistics Window Loss of Signal Loss of PointerErrored Seconds Loss of FrameSeverely Errored Seconds Severely Errored Framing SecondsCode Violations Configuring Broadcast Suppression Token Ring Bridge Mode Setting The Token Ring Bridge Mode Defining the Bridge ModesTransparent Source RoutingUsing the Physical View Windows Etwmim Ethernet Port Physical ViewEthernet Port Physical Status Fields Active PortEtwmim Token Ring Port Physical View Epim TypeToken Ring Physical Status Fields Ring SpeedRing State FNB State Active MonitorUsing the Interface Configuration Window Defining the Bridge Method 29. Interface ConÞguration WindowSetting the Bridge Method NetBIOSDefining the Protocol Transmission OtherUsing the Bridge and Port Configuration Windows From the Bridge Status window Virtual Ring Number Ring NumberPort Mode Novell TranslationBridge Mode/Explorer Type Configuring SmartTrunking Port NameMode SmartTrunk StateInstance # SmartTrunksBridging Bridging 100 Configuring SmartTrunking Index Index-2 Index-3 Index-4
Related manuals
Manual 88 pages 62.16 Kb Manual 275 pages 3.4 Kb

CSX200, CSX400 specifications

Cabletron Systems was a leading developer of networking solutions, and its CSX400 and CSX200 series of high-performance switches represent some of the key innovations in the field of enterprise networking during their time. Both models were geared towards enhancing network reliability, efficiency, and speed, particularly in environments where heavy data traffic and complex networking demands were prevalent.

The CSX400, designed for larger enterprises, boasts a robust architecture capable of handling significant throughput. One of its standout features is its stackable design, allowing multiple switches to be interconnected and managed seamlessly as a single unit. This scalability provides organizations with the flexibility to expand their networks without significant infrastructure overhauls. The CSX400 supports various Ethernet standards, including 10/100 Ethernet and Gigabit Ethernet, positioning it to effectively manage both legacy and modern networking requirements.

In addition to its scalability, the CSX400 is distinguished by its advanced Layer 2 and Layer 3 routing capabilities. This dual-layer functionality enables efficient data handling and is instrumental in managing traffic between different network segments. Moreover, the switch incorporates features like VLAN (Virtual Local Area Network) support and Quality of Service (QoS) prioritization, allowing for enhanced performance of critical applications and streamlined bandwidth allocation.

On the other hand, the CSX200 series is tailored for smaller enterprises or branch offices needing a reliable yet efficient networking solution. Despite its compact design, the CSX200 is equipped with essential features that promote effective network management and security. It offers a simplified management interface, making it user-friendly for network administrators. The switch also provides essential access control measures, employing technologies like IEEE 802.1X for network access security.

Both the CSX400 and CSX200 prioritize performance through the incorporation of advanced switching technologies. They support features such as Spanning Tree Protocol (STP), enabling loop-free topologies and enhanced network resilience. These attributes are particularly crucial in dynamic networking environments where downtime can have significant repercussions on business operations.

Overall, Cabletron Systems' CSX400 and CSX200 series represent a blend of scalability, advanced routing capabilities, and user-friendly management, making them vital assets for organizations looking to optimize their network infrastructure during a period of rapid technological evolution. With their rich feature sets and unwavering performance, these switches helped pave the way for modern networking solutions that cater to diverse enterprise needs.
Top Page Image Contents