Dedicated to dual uplink networks
Easy to configure
Smart link group
A smart link group consists of only two member ports: the master and the subordinate ports. Only one
port is active for forwarding at a time, and the other port is blocked and in the standby state. When link
failure occurs on the active port due to port shutdown or the presence of a unidirectional link, for
example, the standby port becomes active to take over, and the original active port transits to the
As shown in
link group, with Port1 being active and Port2 being standby.
Master port and slave (subordinate) port are two port roles in a smart link group. When both ports in a
smart link group are up, the master port preferentially transits to the forwarding state, and the
subordinate port stays in the standby state. Once the master port fails, the subordinate port takes over to
forward traffic. As shown in
master ports, and Port2 of Device C and Port2 of Device D subordinate ports.
The link that connects the master port in a smart link group is the master link. The link that connects the
subordinate port is the subordinate link.
Flush messages are used by a smart link group to notify other devices to refresh their MAC address
forwarding entries and ARP/ND entries when link switchover occurs in the smart link group. Flush
messages are common multicast data packets and will be dropped by a blocked receiving port.
A smart link group controls the forwarding state of some data VLANs (protected VLANs). Different smart
link groups on a port control different protected VLANs. The state of the port in a protected VLAN is
determined by the state of the port in the smart link group.
Transmit control VLAN
The transmit control VLAN is used for transmitting flush messages. When link switchover occurs, the
devices (such as Device C and Device D in
Receive control VLAN
The receive control VLAN is used for receiving and processing flush messages. When link switchover
occurs, the devices (such as Device A, Device B, and Device E in
messages in the receive control VLAN and refresh their MAC address forwarding entries and ARP/ND
24, Port1 and Port2 of Device C and Port1 and Port2 of Device D each form a smart
24, you can configure Port1 of Device C and Port1 of Device D as
24) broadcast flush messages within the transmit
24) receive and process flush