Introduction to Filtering

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Introduction to Filtering

This router provides programmable filtering which gives you the ability to control under what conditions Ethernet frames are forwarded from one network to another. There are many reasons why this might need to be accomplished, some of which are security, protocol discrimination, bandwidth conservation, and general restrictions.

Filtering may be accomplished by using two different methods. The first method is to filter or forward frames based solely on their source or destination MAC address. This method of filtering is useful when bridging between LANs and for providing remote access security in any type of network. The Ethernet MAC (Media Access Control) address is checked against the addresses in the filtering list and the frame is filtered or forwarded accordingly.

The second method of filtering is pattern filtering where each frame is checked against a filter pattern. The filter pattern may be defined to perform a check of any portion of the Ethernet frame. Separate filter patterns may be defined for bridged frames, IP routed frames, and IPX routed frames.

For more information on filtering, please refer to the Programmable Filtering section of the router Reference Manual located on the accompanying CD-ROM.

MAC Address Filtering

MAC address filtering is provided by three built-in functions.

The first function is “Filter if Source”; the second is “Filter if Destination.” The third function allows you to change the filter operation from “positive” to “negative.” The positive filter operation causes frames with the specified MAC addresses to be filtered. The negative filter operation causes frames with the specified MAC addresses to be forwarded.

You may easily prevent any station on one segment from accessing a specific resource on the other segment; for this, “positive” filtering and the use of “Filter if Destination” would be appropriate. If you want to disallow a specific station from accessing any service, “Filter if Source” could be used.

You may easily prevent stations on one segment from accessing all but a specific resource on the other segment; for this, “negative” filtering and the use of “Forward if Destination” would be appropriate. If you want to disallow all but one specific station from accessing any service on the other segment, the use of “Forward if Source” could be used.

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Black Box LR5200A-R2, LR5100A-T manual Introduction to Filtering, MAC Address Filtering
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LR5200A-R2, LR5100A-T specifications

The Black Box LR5100A-T and LR5200A-R2 are advanced network media converters designed to facilitate seamless data transmission across various media types. These devices are particularly valuable for organizations seeking high-performance solutions for extending network communications beyond traditional limits.

The LR5100A-T is an Ethernet media converter that operates over twisted pair cabling, efficiently converting 10/100/1000 Mbps Ethernet signals into fiber optic signals. This capability allows businesses to harness the long-distance advantages of fiber optics while maintaining compatibility with existing Ethernet infrastructure. With a broad range of supported distances, users can effectively communicate over distances up to 100 kilometers, depending on the type of fiber optic cable used and the transmission rate.

In contrast, the LR5200A-R2 emphasizes compatibility with a wider range of fiber types and supports both multimode and single-mode fiber connections. It also provides auto-negotiation capabilities, which enable it to automatically detect and configure to the optimal speed of connected devices, streamlining setup and enhancing user experience.

One of the key features of both the LR5100A-T and LR5200A-R2 is their rugged design, making them suitable for deployment in harsh environments. They are engineered to withstand extreme temperatures and are resistant to vibration, ensuring reliability in challenging settings. Additionally, both models adhere to industry standards, ensuring interoperability with a diverse array of networking equipment.

Notably, these converters come equipped with LED indicators that allow for real-time monitoring of device status, simplifying network management and troubleshooting. This feature ensures that technicians are promptly alerted to any connectivity issues, significantly reducing downtime.

Powering options for both models include standard AC power supplies or Power over Ethernet (PoE), allowing for flexible deployment scenarios without the need for additional power outlets. This flexibility can be a crucial factor in environments where power availability may be limited.

With their blend of performance, durability, and advanced features, the Black Box LR5100A-T and LR5200A-R2 media converters represent a solid choice for organizations looking to future-proof their network infrastructure while ensuring high levels of connectivity and reliability. Whether extending existing networks or implementing new solutions, these devices provide the necessary tools for effective communication in today’s digital world.
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