Cisco Systems BC-109 manual Enable or Disable the Source-Route Fast-Switching Cache

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Tune the SRB Network

Enable or Disable the Source-Route Fast-Switching Cache

Rather than processing packets at the process level, the fast-switching feature enables the Cisco IOS software to process packets at the interrupt level. Each packet is transferred from the input interface to the output interface without copying the entire packet to main system memory. Fast switching allows for faster implementations of local SRB between 4/16-MB Token Ring cards in the same router, or between two routers using the 4/16-Mb Token Ring cards and direct encapsulation.

By default, fast-switching software is enabled when SRB is enabled. To enable or disable source-route fast-switching, use one of the following commands in interface configuration mode:

Command

Purpose

source-bridge route-cache

Enable fast-switching.

 

 

no source-bridge route-cache

Disable fast-switching.

 

 

Note Using either NetBIOS Byte Offset access filters or access expressions that combine access filters disables the fast switching of source-route bridging frames.

Enable or Disable the Source-Route Autonomous-Switching Cache

Autonomous switching is a feature that enables the Cisco IOS software to transmit packets from the input ciscoBus card to the output ciscoBus card without any involvement on the part of the router processor.

Autonomous switching is available for local SRB between ciscoBus Token Ring (CTR) cards in the same router. Autonomous switching provides higher switching rates than does fast switching between 4/16-Mb Token Ring cards. Autonomous switching works for both two-port bridges and multiport bridges that use ciscoBus Token Ring cards.

In a virtual ring that includes both ciscoBus Token Ring and 4/16-Mb Token Ring interfaces, frames that flow from one CTR interface to another are autonomously switched, and the remainder of the frames are fast switched. The switching that occurs on the CTR interface takes advantage of the high-speed ciscoBus controller processor.

To enable or disable source-route autonomous switching, use one of the following commands in interface configuration mode:

Command

Purpose

source-bridge route-cache cbus

Enable autonomous switching.

 

 

no source-bridge route-cache cbus

Disable autonomous switching.

 

 

Note Using either NetBIOS Byte Offset access filters or access-expressions that combine access filters disables the autonomous switching of SRB frames.

BC-140Bridging and IBM Networking Configuration Guide

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Contents Configuring Source-Route Bridging SRB Configuration Task ListConfigure Source-Route Bridging Configure a Dual-Port BridgeConfigure a Multiport Bridge Using a Virtual Ring Multiple Dual-Port BridgesNo source-bridge ring-group ring-group Define a Ring Group in SRB ContextSource-bridge ring-group ring-group Configure SRB over Fddi Enable SRB and Assign a Ring Group to an InterfaceInterface fddi slot/port Source-bridge route-cache cbusConfigure Fast-Switching SRB over Fddi Configure SRB over Frame RelayEnable the Automatic Spanning-Tree Function Limit the Maximum SRB Hops Configure Bridging of Routed Protocols Enable Use of the RIFConfigure a Static RIF Entry Configure the RIF Timeout IntervalOverview of SR/TLB Following notes and caveats apply to all uses of SR/TLB Enable Bridging between Transparent Bridging and SRB Disable Fast-Switched SR/TLBEnable Translation Compatibility with IBM 8209 Bridges No source-bridge transparent ring-group fastswitchEnable Token Ring LLC2-to-Ethernet Conversion Enable 0x80d5 ProcessingEnable Standard Token Ring LLC2-to-Ethernet LLC2 Conversion Source-bridge sap-80d5 dsapConfigure NetBIOS Support Specify Timeout and Enable NetBIOS Name Caching Source-bridge proxy-netbios-onlyConfigure the NetBIOS Cache Name Length Enable NetBIOS ProxyingCreate Static Entries in the NetBIOS Name Cache Specify Dead-Time Intervals for NetBIOS PacketsNetbios name-cache recognized-timeout seconds Configure LNM SupportNetbios name-cache query-timeout seconds LNM Linking to a Source-Route Bridge on Each Local Ring How a Router Works with LNM LAN Network Manager Monitoring and TranslatingDisable LNM Functionality Disable Automatic Report Path Trace Function Enable Other LRMs to Change Router ParametersChange Reporting Thresholds Apply a Password to an LNM Reporting LinkEnable LNM Servers Lnm softerr milliseconds Change an LNM Reporting IntervalMonitor LNM Operation Secure the SRB Network Configure NetBIOS Access FiltersConfigure NetBIOS Access Filters Using Station Names Configure NetBIOS Access Filters Using a Byte Offset Netbios access-list host name permit deny patternNetbios access-list bytes name permit deny offset Netbios input-access-filter bytes nameFilter Frames by Protocol Type Configure Administrative Filters for Token Ring TrafficNetbios output-access-filter bytes name Filter Destination Addresses Filter Frames by Vendor CodeFilter Source Addresses Access Expression Example Configure Access Expressions Optimize Access ExpressionsAlter Access Lists Used in Access Expressions Tune the SRB NetworkEnable or Disable the Source-Route Fast-Switching Cache Optimize Explorer Processing Enable or Disable the SSEEstablish the Connection Timeout Interval Controlling Explorer Storms in Redundant Network Topologies Mac-address ieee-address Configure Proxy ExplorersEstablish SRB Interoperability with TI MAC Firmware Report Spurious Frame-Copied Errors Monitor and Maintain the SRB NetworkSRB Configuration Examples Source-bridge tcp-queue-max numberDual-Port Source-Route Bridge Configuration Basic SRB with Spanning-Tree Explorers ExampleOptimized Explorer Processing Configuration Example SRB-Only ExampleSRB and Routing Certain Protocols Example Multiport SRB ExampleConfiguration for Router a SRB with Multiple Virtual Ring Groups ExampleSRB over Fddi Configuration Examples SRB over Fddi Fast-Switching ExampleConfiguration for Router B Router aSRB over Frame Relay Configuration Example Frad Using SRB over Frame Relay to Connect to a Cisco RouterConfiguration of Router a Configuration on Router BConfiguration on Router C Adding a Static RIF Cache Entry ExampleAdding a Static RIF Cache Entry for a Two-Hop Path Example SR/TLB for a Simple Network ExampleBC-154Bridging and IBM Networking Configuration Guide SR/TLB with Access Filtering Example Example of a Bit-Swapped AddressNetBIOS Support with a Static NetBIOS Cache Entry Example Specifying a Static EntryWayfarer# show lnm config LNM for a Simple Network ExampleLNM for a More Complex Network Example NetBIOS Access Filters Example Filtering Bridged Token Ring Packets to IBM Machines Example Shows a router connecting four Token Rings Creating Access Filters Example Following access expression would resultAccess Filters Example Fast-Switching ExampleAutonomous Switching Example
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