D-Link DGS-3312SR Release 3.5 Manual page 57

Flow Control
Learning
Click Apply to implement changes made.
DGS-3312SR Stackable Gigabit Layer 3 Switch
The Switch allows the user to configure two types of gigabit connections;
1000M/Full_M and 1000M/Full_S. Gigabit connections are only supported in full
duplex connections and take on certain characteristics that are different from the
other choices listed.
The 1000M/Full_M (master) and 1000M/Full_S (slave) parameters refer to
connections running a 1000BASE-T cable for connection between the Switch port
and other device capable of a gigabit connection. The master setting
(1000M/Full_M) will allow the port to advertise capabilities related to duplex, speed
and physical layer type. The master setting will also determine the master and slave
relationship between the two connected physical layers. This relationship is
necessary for establishing the timing control between the two physical layers. The
timing control is set on a master physical layer by a local source. The slave setting
(1000M/Full_S) uses loop timing, where the timing comes form a data stream
received from the master. If one connection is set for 1000M/Full_M, the other side
of the connection must be set for 1000M/Full_S. Any other configuration will result
in a link down status for both ports.
Displays the flow control scheme used for the various port configurations. Ports
configured for full-duplex use 802.3x flow control, half-duplex ports use
backpressure flow control, and Auto ports use an automatic selection of the two.
The default is Disabled.
Enable or disable MAC address learning for the selected ports. When Enabled,
destination and source MAC addresses are automatically listed in the forwarding
table. When learning is Disabled, MAC addresses must be manually entered into
the forwarding table. This is sometimes done for reasons of security or efficiency.
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