Netgear XCM8806 Chassis User Manual - Page 443

Disconnecting a Device, Disconnecting and Reconnecting a Device

Page 443 highlights

NETGEAR 8800 User Manual Device A EX_176 Figure 29. Single Device with MAC Lockdown Timeout Disconnecting a Device In this example, Device A is disconnected from the port, triggering a port-down action. The MAC entry for Device A is removed from the hardware FDB; however, the MAC entry for the device is maintained in the software. The MAC lockdown timer for this entry starts when the port goes down. After 3,000 seconds, the MAC entry for Device A is removed from the software. Disconnecting and Reconnecting a Device When Device A is disconnected from the port, the resulting port-down action causes the MAC entry for Device A to be removed from the hardware FDB. The MAC entry in software is maintained, and the MAC lockdown timer is started for the port. After only 1,000 seconds have elapsed, Device A is reconnected to the same port and starts sending traffic. A MAC entry is created in the hardware FDB, and the MAC lockdown timer is restarted for the MAC entry in the software. If Device A is reconnected but does not send any traffic for 3,000 seconds, no MAC entry is created in the hardware FDB, and the MAC lockdown timer will expire after reaching 3,000 seconds. Disconnecting and Reconnecting Devices with MAC Limit Learning In this example, a MAC learning limit of 1 has also been configured on the ports in addition to the MAC lockdown timer of 3000 seconds. When Device A is disconnected, the resulting port-down action removes the MAC entry for Device A from the hardware FDB. The MAC entry for Device A is maintained in the software, and the MAC lockdown timer for this entry is restarted when the port goes down. After 1000 seconds, a different device is connected to the same port and starts sending traffic. Because the MAC learning limit is set to 1 and the MAC lockdown timer is still running, the MAC address of the new device is not learned. Instead, the new MAC address is blackholed in the hardware. When the MAC lockdown timer for Device A expires, its MAC entry is removed from the software. If the new device is still connected to the same port and sends traffic, the MAC address for the new device is learned and added to the FDB. The MAC lockdown timer for the new device is started, and the blackhole entry that was created for this device is deleted. Chapter 17. Security | 443

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Chapter 17.
Security
|
443
NETGEAR 8800 User Manual
Figure 29. Single Device with MAC Lockdown Timeout
Disconnecting a Device
In this example, Device A is disconnected from the port, triggering a port-down action. The
MAC entry for Device A is removed from the hardware FDB; however, the MAC entry for the
device is maintained in the software. The MAC lockdown timer for this entry starts when the
port goes down.
After 3,000 seconds, the MAC entry for Device A is removed from the software.
Disconnecting and Reconnecting a Device
When Device A is disconnected from the port, the resulting port-down action causes the
MAC entry for Device A to be removed from the hardware FDB. The MAC entry in software is
maintained, and the MAC lockdown timer is started for the port.
After only 1,000 seconds have elapsed, Device A is reconnected to the same port and starts
sending traffic. A MAC entry is created in the hardware FDB, and the MAC lockdown timer is
restarted for the MAC entry in the software.
If Device A is reconnected but does not send any traffic for 3,000 seconds, no MAC entry is
created in the hardware FDB, and the MAC lockdown timer will expire after reaching 3,000
seconds.
Disconnecting and Reconnecting Devices with MAC Limit Learning
In this example, a MAC learning limit of 1 has also been configured on the ports in addition to
the MAC lockdown timer of 3000 seconds.
When Device A is disconnected, the resulting port-down action removes the MAC entry for
Device A from the hardware FDB. The MAC entry for Device A is maintained in the software,
and the MAC lockdown timer for this entry is restarted when the port goes down.
After 1000 seconds, a different device is connected to the same port and starts sending
traffic. Because the MAC learning limit is set to 1 and the MAC lockdown timer is still running,
the MAC address of the new device is not learned. Instead, the new MAC address is
blackholed in the hardware.
When the MAC lockdown timer for Device A expires, its MAC entry is removed from the
software. If the new device is still connected to the same port and sends traffic, the MAC
address for the new device is learned and added to the FDB. The MAC lockdown timer for
the new device is started, and the blackhole entry that was created for this device is deleted.
EX_176
Device A