IBM 8260 manual Filtering for Bridging Functions, Transparent Bridging Filtering Database

This parameter allows you to enable/disable SNAP conversion between token-ring and Ethernet frames. When enabled, the Ethernet network is treated as an 802.3 network. When disabled, the Ethernet network is treated as an Ethernet V2 network. Note that the implication of this parameter is that the Ethernet ports can be either Ethernet V2 or 802.3 but not both.

∙IPX Conversion

When enabled, IPX packets are recognized and processed by the module for bridging between token-ring and Ethernet. If disabled, problems may arise when IPX stations try to pass data from Ethernet to token-ring networks.

11.8.5Filtering for Bridging Functions

When performing transparent bridging (for both TB and SRT) the Multiprotocol Interconnect module will always use its filtering database to forward or discard the frames that it receives on each of its TB or SRT (for transparent bridging part only) ports. Additionally, via configuration parameters, you can define the following filtering options for each port:

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Normal or security mode for each TB port and TB part of SRT ports

Broadcast/multicast filtering for TB ports and TB part of SRT ports

Custom filtering for any bridging port regardless of the bridging type configured for that port

These filtering options allow you to forward or discard frames based on one or more filters strung together. If the frame matches the specified filtering criteria, it may be either discarded or forwarded with a specified priority. The following sections describe the details of various filtering options provided by the Multiprotocol Interconnect module.

11.8.5.1 Transparent Bridging Filtering Database

The Multiprotocol Interconnect module provides a global filtering database to support all the interfaces on the module using transparent bridging and the transparent bridging part of the source-route transparent bridging. This database is used to determine which frames are to be forwarded and which frames are to be discarded by the bridging function in the Multiprotocol Interconnect module.

This table is updated automatically as new addresses are learned by the Multiprotocol Interconnect module. You can also configure the filtering database with permanent entries.

The contents of the filtering database can be displayed by selecting Filtering Database from the Bridge Menu. Figure 157 on page 271 shows an example to the filtering database which is displayed.

270 8260 Multiprotocol Intelligent Switching Hub