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Used with transparent bridges to learn hardware addresses
of all devices on an internetwork. The switch then filters the network
with the known hardware (MAC) addresses. [TOC]
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Bridge Protocol Data Unit: A Spanning-Tree Protocol initializing
packet that is sent at definable intervals for the purpose of exchanging
information among bridges in the network. [TOC]
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A frame-switching technique that flows data through a
switch so that the leading edge exits the switch at the output port before
the packet finishes entering the input port. Frames will be read, processed,
and forwarded by devices that can use cut-through switching as soon as
the destination address of the frame is confirmed and the outgoing port
is identified. [TOC]
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Used with Spanning-Tree Protocol (STP) to designate forwarding
ports. If there are multiple links to the same networks, STP will shut
a port down to stop network loops. [TOC]
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LAN switch type that reads into the data section of a
frame to make sure fragmentation did not occur. Sometimes called modified
cut-through. [TOC]
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The Spanning-Tree Protocol tells a port on a layer-2 switch
to stop transmitting and creating a network loop. Only designated ports
can send frames. [TOC]
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Used with Spanning-Tree Protocol to stop network loops
from occurring. The root bridge is elected by having the lowest bridge
ID. The bridge ID is determined by priority(32,768 by default on all bridges
and switches) and the main hardware address of the device. The root bridge
determines which of the neighboring layer-2 devices' interface becomes
the designated and nondesignated ports. [TOC]
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| (STP): The bridge protocol (IEEE802.1d) that enables a learning bridge to dynamically avoid loops in the network topology by creating a spanning tree using spanning tree algorithm. Spanning-tree frames called bridge protocol data units (BPDUs) are sent and received by all switches in the network at regular intervals. The switches participating in the spanning tree don't forward the frames; instead, they're processed to determine the spnning-tree topology itself. Cisco Catalyst series switches use STP 802.1d to perform this function. [TOC] | |
| Technique in which the switch first copies each packet into its buffers and performs cyclical redundancy check (CRC). If the packet is error-free, the switch then looks up the destination address in its filter table, determine the appropriate exit port, and sends the packet. [TOC] | |