SMC Networks 7724M/VSW - annexe 1, Manual

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CLI Management Guide
TigerAccess™ EE
262 SMC7824M/VSW
•
Learning
the port is preparing to forward data traffic. The port waits for a period of time to build
its MAC address table before actually forwarding data traffic. This time is the
forwarding delay.
•
Forwarding
After some time learning address, it is allowed to forward data frame. This is the
steady state for a switch port in the active spanning tree.
• Disabled
When disabled, a port will neither receive nor transmit data or BPDUs. A port is in this
state because it is broken or disabled by administrator.
8.3.2 RSTP Operation
STP or RSTP is configured on network where Loop can be created. However, RSTP is
more rapidly progressed than STP at the stage of reaching to the last topology. This sec-
tion describes how the RSTP more improved than STP works. It contains the below sec-
tions.
• Port States
•
BPDU Policy
• Rapid Network Convergence
• Compatibility with 802.1d
8.3.2.1 Port States
RSTP defines port states as discarding, learning, and forwarding. Blocking of 802.1d and
listening is combined into discarding. Same as STP, root port and designated port are de-
cided by port state. But a port in blocking state is divided into alternate port and backup
port. An alternate port means a port blocking BPDUs of priority of high numerical value
from other switches, and a backup port means a port blocking BPDUs of priority of high
numerical value from another port of same equipment.
Switch B
Switch A
Alternate
Port
Switch C
Switch D
Backup
Port
Path 2 Path 1
ROOT
Designated
Port
Fig. 8.15 Alternate Port and Backup port