CHAPTER 4
ADVANCED TOPICS
This TigerSwitch 1000 supports Layer 2 switching and other advanced features, which are described in this chapter.
Layer 2 Switching
When a frame enters a port, its destination MAC address is checked in the address database to see which port leads to this destination. If the destination address belongs to the incoming port, the frame is dropped or “filtered” because it addressed to the local segment. If the destination address if found on another port, the frame is forwarded to that port and queued for output. But, if the destination address is not found in the address database, the frame is sent to one or more output ports based on the rules for handling tagged or untagged VLAN frames.
If the source MAC address of the frame was not found in the address database, it is recorded along with the incoming port number where it entered the switch. This information is then used to make later decisions for frame forwarding.
Switching involves the following steps:
◆VLAN Classification
◆Learning
◆Filtering
◆Forwarding
◆Aging
