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I. Half-duplex mode uses back pressure flow control to prevent the receiving
buffer from being overrun by data from a source node.
II. Full-duplex mode uses 802.3x flow control standard to prevent fast data traffic
from overrunning slow data traffic.
III. Auto-sensing mode is in use after auto-negotiating with the other end of the link.
After VLAN classification, the switch checks the <source MAC address, VLAN> pair in the
switching database (SDB) to see whether the <source MAC address, VLAN> pair is known.
- If it is unknown, the switch inserts the <source MAC address, VLAN> into the SDB
and learns the <source MAC address, VLAN>.
- If it is known, the switch checks the <source MAC address, VLAN> for a mis
matched port ID. If the port ID associated with the <source MAC address, VLAN>
pair in the SDB is different than the receiving port, the switch modifies the port ID in
the SDB and modifies its management database (MDB) accordingly.
After learning the address, the switch checks:
- Whether the source port or destination port is in the forwarding state.
- Whether the source MAC address or destination MAC address is to be filtered.
- Whether the source port ID is the same as destination port ID.
If any of these conditions are met, the switch drops the receiving. Otherwise, it continues with
the forwarding process described below.
During the forwarding process, the switch checks whether the <destination MAC address,
VLAN> pair is unknown.
- If it is unknown, the switch floods the receiving frame to all ports in the VLAN,
excluding the source port.
- If it is known, the switch forwards the receiving frame to the port associated
with the <destination MAC address, VLAN> pair. At the same time, the switch
ascertains the individual’s ports VLAN tagging and/or un-tagging configuration
and corresponding VLAN ID render the appropriate frame tagging when the frame
is ready to be transmitted.
Manageable 8/9-Port Switch
User’s Manual 6