Cabletron Systems CSX200, CSX400 Ethernet and Token Ring Special Filter Databases, 4-49, Bridging

Bridging

To delete an address:

1.Click to highlight the address entry in the Address Entry panel that you wish to delete from the filtering database.

2.Click on .

Clearing All Permanent, Static, or Dynamic Entries

To erase all Permanent, Static, or Dynamic entries from the Filtering Database,

click on the associated button in the upper portion of the window.

Ethernet and Token Ring Special Filter Databases

While the Filtering Database deÞnes Þlters for all packets from a particular source address, the Ethernet Special Filter Database and the Token Ring Special Filtering Databases allow you to Þlter packets through an Ethernet or a Token Ring bridge, respectively, using a special Þltering scheme.

When a packet is received at an Ethernet bridging interface, it is Þrst checked against the Ethernet Special Filter Database to see if any Þltering action applies to it. Because of this, an entry in the Ethernet Special Filter Database takes precedence over a Þlter entry in the Filtering Database that would otherwise apply to the packet.

The Ethernet Special Filter Database allows you to:

¥DeÞne and save a Þlter based on a combination of Source Address, Destination Address, Ethernet Data Type and Data (including the offset).

¥Specify the receive ports at which the Þlter will take effect.

¥Specify the forwarding/Þltering action at each bridging port of the device.

When checking for Transparent Þltering information, the bridge Þrst checks the Token Ring Special Filter Database to see if any Þltering action applies to it. Because of this, a Þlter entry in the Token Ring Special Filter Database takes precedence over a Þlter entry in the Filtering Database that would otherwise apply to the packet.

Looking at each enabled Þlter, starting with the lowest numbered Þlter, the bridge compares the following Þelds to the corresponding Þelds in the received packet:

¥Destination address

¥Source address

¥Ethernet or Token Ring data type

¥Up to 16 hex integers (64 bytes) of the data Þeld

In addition, a Þlter can also specify at which port or ports the packet must be received for the Þlter to be applicable. If a received packet matches all the contents of an enabled Þlter, the bridge forwards the packet to the deÞned set of ports.

Ethernet and Token Ring Special Filter Databases 4-49