Cisco Systems BC-23 manual Filtering LAT Service Announcements, BC-51

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Configuring Transparent Bridging

Transparent and SRT Bridging Configuration Task List

Filtering LAT Service Announcements

The bridging software allows you to filter LAT frames. LAT bridge filtering allows the selective inclusion or exclusion of LAT multicast service announcements on a per-interface basis.

Note The LAT filtering commands are not implemented for Token Ring interfaces.

In the LAT protocol, a group code is defined as a decimal number in the range 0 to 255. Some of the LAT configuration commands take a list of group codes; this is referred to as a group code list. The rules for entering numbers in a group code list follow:

•Entries can be individual group code numbers separated with a space. (The Digital LAT implementation specifies that a list of numbers be separated by commas; however, our implementation expects the numbers to be separated by spaces.)

•Entries can also specify a range of numbers. This is done by separating an ascending order range of group numbers with hyphens.

•Any number of group codes or group code ranges can be listed in one command; just separate each with a space.

In LAT, each node transmits a periodic service advertisement message that announces its existence and availability for connections. Within the message is a group code list; this is a mask of up to 256 bits. Each bit represents a group number. In the traditional use of LAT group codes, a terminal server only will connect to a host system when there is an overlap between the group code list of the user on the terminal server and the group code list in the service advertisement message. In an environment with many bridges and many LAT hosts, the number of multicast messages that each system has to deal with becomes unreasonable. The 256 group codes might not be enough to allocate local assignment policies, such as giving each DECserver 200 device its own group code in large bridged networks. LAT group code filtering allows you to have very fine control over which multicast messages actually get bridged. Through a combination of input and output permit and deny lists, you can implement many different LAT control policies.

You can filter LAT service advertisements by performing any of the tasks in the following sections:

•Enabling LAT Group Code Service Filtering

•Specifying Deny or Permit Conditions for LAT Group Codes on Input

•Specifying Deny or Permit Conditions for LAT Group Codes on Output

Enabling LAT Group Code Service Filtering

You can specify LAT group-code filtering to inform the system that LAT service advertisements require special processing. To enable LAT group-code filtering, use the following command in global configuration mode:

Command

Purpose

 

 

bridge bridge-grouplat-service-filtering

Enables LAT service filtering.

 

 

Specifying Deny or Permit Conditions for LAT Group Codes on Input

You can specify the group codes by which to deny or permit access upon input. Specifying deny conditions causes the system to not bridge any LAT service advertisement that contain any of the specified groups. Specifying permit conditions causes the system to bridge only those service advertisements that match at least one group in the specified group list.

Cisco IOS Bridging and IBM Networking Configuration Guide

BC-51

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Contents BC-23 Transparent and SRT BridgingBC-24 Transparent Bridging FeaturesIntegrated Routing and Bridging BC-25 Bridge-Group Virtual InterfaceBridge-Group Virtual Interface in the Router BC-26BC-27 SRT Bridging FeaturesOther Considerations BC-28 Transparent and SRT Bridging Configuration Task ListAssigning Each Network Interface to a Bridge Group Configuring Transparent Bridging and SRT BridgingAs Ieee 802.1D standard, DEC or Vlan bridge BC-29Transparently Bridged VLANs for ISL Command PurposeChoosing the OUI for Ethernet Type II Frames BC-30Transparently Bridged VLANs on an Fddi Backbone BC-31BC-32 Routing between ISL VLANsSubinterface with the Vlan Specifies a subinterfaceSame bridge group BC-33Configuring Transparent Bridging over WANs Configuring a Subscriber Bridge GroupConfiguring Fast-Switched Transparent Bridging over ATM BC-34Command Configuring Transparent Bridging over DDRDefining the Protocols to Bridge Specifying the Bridging ProtocolDetermining Access for Bridging Configuring Transparent Bridging over Frame RelayConfiguring an Interface for Bridging Fast-Switched Transparent BridgingBridging in a Frame Relay Network with No Multicasts Configuring Transparent Bridging over Multiprotocol LapbBridging in a Frame Relay Network with Multicasts BC-37Configuring Transparent Bridging over Configuring Transparent Bridging over SmdsSpecifies IP-to-X.121 mapping BC-38Configuring Integrated Routing and Bridging Configuring Concurrent Routing and BridgingSpecifies a protocol to be routed on a bridge group BC-39Configuring the Bridge-Group Virtual Interface Configuring InterfacesEnabling Integrated Routing and Bridging BC-40BC-41 Configuring Protocols for Routing or BridgingBC-42 Configuring Transparent Bridging OptionsDisabling IP Routing BC-43 Configuring LAT CompressionEnabling Autonomous Bridging BC-44 Establishing Multiple Spanning-Tree DomainsEstablishes a multiple spanning-tree domain Filtering Transparently Bridged Packets Configuring Bridge Table Aging TimeForwarding Multicast Addresses BC-45BC-46 Setting Filters at the MAC LayerFiltering by Vendor Code Filters particular MAC-layer station addressesEthernet-ordered MAC address BC-47BC-48 Filtering by Protocol TypeType Configuration mode Defining and Applying Extended Access ListsInterface BC-49BC-50 BC-51 Filtering LAT Service AnnouncementsEnabling LAT Group Code Service Filtering BC-52 Adjusting Spanning-Tree ParametersSetting an Interface Priority Setting the Bridge PriorityAdjusting Bpdu Intervals Assigning Path CostsDefining the Forward Delay Interval Adjusting the Interval between Hello BPDUsDisabling the Spanning Tree on an Interface Defining the Maximum Idle IntervalBC-55 BC-56 Configuring the PA-12E/2FE Port AdapterBC-57 Monitoring and Maintaining the PA-12E/2FE Port AdapterBC-58 BC-59 BC-60 Configuring Circuit GroupsConfigures a transmission pause interval Configuring Constrained Multicast FloodingDistributes base load on the source MAC address only BC-61BC-62 BC-63 Basic Bridging ExampleBC-64 Concurrent Routing and Bridging ExampleBC-65 Basic Integrated Routing and Bridging ExampleBC-66 Complex Integrated Routing and Bridging ExampleBC-67 Transparently Bridged VLANs Configuration ExampleBC-68 Router OneRouter Two BC-69 Router ThreeBC-70 Routing between VLANs Configuration ExampleEthernet-to-FDDI Transparent Bridging Example BC-71 Ethernet Bridging ExampleRouter/Bridge in Building BC-72 SRT Bridging ExampleConfiguration for the Thule, Greenland Router Configuration for the New York City RouterMulticast or Broadcast Packets Bridging Example BC-73BC-74 Configuration for BridgeTransparent Bridging Example BC-75 Frame Relay Transparent Bridging ExamplesBridging in a Frame Relay Network with No Multicasts BC-76 Transparent Bridging over Multiprotocol Lapb ExampleBridging in a Frame Relay Network with Multicasts BC-77 Transparent Bridging over DDR ExamplesBC-78 Fast-Switched Transparent Bridging over Smds ExampleComplex Transparent Bridging Network Topology Example Bridged Subnetworks with Domains BC-79BC-80 Configuration for Router aConfiguration for Router C Configuration for Router BConfiguration for Router D BC-81BC-82 Fast Ethernet Subscriber Port, Frame Relay Trunk ExampleATM Subscriber Ports, ATM Trunk Example BC-83 BC-84 Configuration of IRB for PA-12E/2FE Port Adapter Example

BC-23 specifications

Cisco Systems has long been a leader in the networking industry, and its BC-23 model exemplifies the company's commitment to innovation and performance. Aimed at enhancing business operations, the BC-23 is tailored for organizations looking for robust solutions that support their digital transformation efforts.

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Security is a top priority, and the Cisco BC-23 incorporates cutting-edge security measures. Integrated threat detection and prevention systems help safeguard sensitive data from cyber threats. Additionally, the device supports secure access protocols, ensuring that only authorized users can connect to the network. This multi-layered security approach not only protects the network infrastructure but also secures the integrity of the data being transmitted.

Another significant characteristic of the BC-23 is its support for software-defined networking (SDN). This technology allows businesses to manage their networks through centralized software applications, facilitating real-time adjustments and optimizations. The flexibility afforded by SDN is especially advantageous in dynamic environments where network demands can shift rapidly.

The Cisco BC-23 also offers enhanced management features, allowing IT teams to monitor network performance and analytics effectively. This visibility into network operations enables organizations to identify potential issues before they escalate, minimizing downtime and keeping business processes smooth.

Furthermore, the BC-23 is designed for scalability. As organizations grow, their networking needs evolve, and the BC-23 can easily adapt to these changes. Businesses can add additional devices and capabilities without the need for a complete overhaul of their existing infrastructure.

With its combination of speed, security, and scalability, the Cisco Systems BC-23 is an invaluable asset for modern businesses. It stands out not just as a networking device but as a comprehensive solution that meets the demands of today's fast-paced, technology-driven environment. As companies continue to leverage digital tools for growth and efficiency, the BC-23 will undoubtedly play a significant role in their success.
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