16.1.9 Port reset function

(1) Overview of Operation

When the active port is changed by an operation command or automatic switch-back, the old active port is temporarily brought down in order to recover the communication immediately. The host switch to which the old active port is connected detects a link down and clears MAC address entries learned on the port from MAC address table.

The following figure shows the differences in switching operations when the port reset function is enabled or disabled.

Figure 16-6: Differences in switch operations between enabling and disabling port reset functionality

Normal operation

The primary port on the Switch performs communication. Upstream switches learn the MAC address of the user terminal via the current communication path.

Switching (Port reset function disabled)

When the port reset function is disabled, even if the active port is switched to the secondary port, the host switch learns MAC address of the user terminal on the previous port, so if MAC address learned on the port disappears or there is no communication from the user terminal, communication will not be restored.

Switching (Port reset function is enabled)

When the port reset function is enabled, the primary port, which is the old active port, is temporarily brought down while the active port is switched to the secondary port. The host switch to which the old active port is connected detects a link down and deletes MAC addresslearned on the port so that communication can be recovered quickly.