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3Com Corporation
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PathBuilder S200 Series Switch
Bridging
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Notice © 1998 3Com Corporation 5400 Bayfront Plaza ® Santa Clara, CA 95052-8145 (408) 326-5000 All rights reserved. Printed in U.S.A. Portions reprinted with the permission of Motorola, Inc. Restricted Rights Notification for U.S. Government Users The software (including firmware) addressed in this manual is provided to the U.S. Government under agreement which grants the government the minimum “restricted rights” in the software, as defined in the Federal Acquisition Regulation (FAR) or the D
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Notice (continued) Proprietary Material Information and software in this document are proprietary to 3Com (or its Suppliers) and without the express prior permission of an officer of 3Com, may not be copied, reproduced, disclosed to others, published, or used, in whole or in part, for any purpose other than that for which it is being made available. Use of software described in this document is subject to the terms and conditions of the 3Com Software License Agreement. This document is for i
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Bridging Overview Functionality PathBuilder S200 series switches support bridging of data traffic for Ethernet LANs. Bridging LAN traffic minimizes your networking costs by eliminating the need for redundant networks and maximizes the availability of dedicated facilities such as servers and printers, as well as public Frame Relay and X.25 services, across multiple LANs. Remote Bridging PathBuilder S200 series switches are intended for use in remote bridging solutions. Solutions This means t
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Mixed LAN Support PathBuilder S200 series switches support mixed LAN bridging, meaning you can configure an Ethernet interface in the same node. Refer to the “Mixed LAN Bridging” section on page 8 for more details. Translational PathBuilder S200 series switches can use the Translational Bridging feature to Bridging bridge traffic between Ethernet Networks. Translational Bridging provides a PathBuilder S200 series switch with the capability to bridge non-routable protocols. For information a
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In This Manual Topic See Page Bridging Features and Capabilities .............................................................. 5 Token Ring LAN ...................................................................................... 6 Ethernet LAN ........................................................................................... 8 Mixed LAN Bridging ............................................................................... 10 MAC Addressing ..........................................
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Topic See Page In This Notice (continued) Bridge Statistics ............................................................................................ 132 Spanning Tree Statistics ........................................................................... 133 Detailed Bridge Link Statistics ................................................................ 135 Bridge Link Filter Summary .................................................................... 138 Transparent Bridge Forwarding Table S
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Bridging Features and Capabilities Bridging Features and Capabilities Introduction This section describes bridging features and capabilities of PathBuilder S200 series switches. Bridging Primer As mentioned earlier, Bridging extends the size and coverage of a Local Area Network (LAN). PathBuilder S200 series switches provide bridging support for up to two 802.3 (Ethernet) LAN interfaces per node or one 802.5 (Token Ring) LAN interface) per node, and up to 32 remote bridge connections. A Pat
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Bridging Features and Capabilities Ethernet LAN What Is It? Ethernet is a common implementation of LAN topology wherein stations are connected using a bus topology. Stations access the Ethernet using Carrier Sense with Multiple Access and Collision Detection (CSMA/CD). PathBuilder S200 PathBuilder S200 series switch Ethernet functionality complies with the IEEE 802.3 Series Switch specifications and provides Transparent Bridging to transport many different Support for protocols over the Wid
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Bridging Features and Capabilities Example of Figure 5 shows an example of two Ethernet LANs connected across a WAN using Ethernet Bridge two PathBuilder S200 series switches as bridges. The example shows a Frame Relay Operation WAN application, but you can also bridge across an X.25 WAN. Frame Relay PB S200 PB S200 Figure 5. Ethernet Bridge Example For More Details... For more details on bridging Ethernet LAN traffic, see Transparent Bridging for Ethernet LANs on page 48. Bridging 7 T0008-16
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Bridging Features and Capabilities Mixed LAN Bridging What is It? PathBuilder S24x, 26x, and 27x switches support a mixture of Token Ring and Ethernet interfaces configured in the same node. This means the PathBuilder S24x, 26x, and 27x switch is able to perform remote Transparent bridging for Ethernet LANs from the same PathBuilder S24x, 26x, and 27x switch as shown in Figure 6. If you happen to configure two Ethernet LAN interfaces in the same node, instead of a mix of one Ethernet and on
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Bridging Features and Capabilities MAC Addressing What Is It? Bridges, whether they using Transparent Bridging, operate at the Data Link Layer, which is concerned with MAC addressing. The MAC Address is a 6-byte MAC (Media Access Control) address that identifies stations on a LAN. The IEEE administers distribution of the MAC address to ensure no duplicates occur in MAC addressing. This is accomplished by assigning a unique MAC address to each manufacturer. Each manufacturer then assigns seq
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Bridging Features and Capabilities LLC2 Local Termination LLC2 Local PathBuilder S200 series switch support includes LLC2 Local Termination for your Termination Bridging operations when passing SNA/SDLC data traffic. LLC2 Local Termination lets specific Token Ring ports generate and respond to LLC2 polls with local acknowledgments, thereby preserving bandwidth and preventing session timeouts. Local Termination, also referred to as “spoofing,” provides an efficient means for carrying out an
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Bridging Features and Capabilities Autolearn for Local Termination What Is It? Local Termination Autolearn reduces the amount of configuration you need to do by letting you spoof remote sessions without configuring a MAC address and a Service Access Point (SAP) for each station running a session to the host Front End Processor (FEP). Since Local Termination supports up to 256 sessions for the PathBuilder S24x, 26x, and 27x switch, Local Termination Autolearn can save you considerable time d
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Bridging Features and Capabilities Filtering What Is It? Filtering lets you restrict data traffic from certain segments of your network. There are different methods used to filter data traffic on a bridged network. PathBuilder S200 series switch support for filtering includes: • MAC Address Filtering • NetBIOS Name Filtering • Protocol Filtering Mac Address MAC Addressing is important in a bridging operation because one of the most Filtering common tasks in a bridging environment is to provid
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Bridging Features and Capabilities Spanning Tree Protocol What Is It? Spanning Tree Protocol reduces multiple bridge paths between LANs to a single path. Instead of a mesh network with several paths to a destination, the Spanning Tree Protocol remaps the network so that only one path is active for traffic between any source station and any destination station. The other paths block any frames between the LANs. A spanning tree network eliminates parallel paths and traffic loops. The PathBui
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Bridging Features and Capabilities Dual Ethernet LANs What Is It? The PathBuilder S24x, 26x, and 27x switch supports up to two Ethernet LANs in t he same node. This means you can connect up to two Ethernet LANs to a single PathBuilder S24x, 26x, and 27x switch to perform bridging and routing of LAN traffic across the WAN to multiple Ethernet LANs. Before Dual Ethernet LAN, the PathBuilder S24x, 26x, and 27x switch supported only one Ethernet LAN port for remote bridging and routing of LAN t
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Basic Remote Bridging Examples Basic Remote Bridging Examples Introduction This section shows some common examples of bridging applications using PathBuilder S200 series switches. Remote Bridging Figure 9 shows a common Source Route Bridging operation for PathBuilder S200 Across a WAN series switches where two Token Ring LANs are attached across a WAN. For example, two LANs could be bridged using two PathBuilder S200 series switches interconnected by an X.25 or Frame Relay link. Bridged traf
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Basic Remote Bridging Examples A Less Complex Figure 11 shows a possible arrangement of SVCs (PVCs for Frame Relay) that Extended Bridge produces the same bridge arrangement as shown in Figure 10. Node 1 Node 2 Bridge 1 Bridge 1 Token Token Ring 1 Ring 2 Bridge 2 Bridge 3 SVC Connectors Node 3 Bridge 2 Token Ring 3 Bridge 3 Figure 11. Example of Bridges in an SVC Arrangement In this arrangement, all LAN segments are one hop away from each other since they are directly attached by a single pai
