Terminology; How Smart Link Works - HPE FlexFabric 5700 Series Configuration Manual

Terminology

Smart link group
A smart link group consists of only two member ports: the primary and the secondary ports. Only one
port is active for forwarding at a time, and the other port is blocked and in standby state. When link
failure occurs on the active port due to port shutdown or the presence of unidirectional link, the
standby port becomes active and takes over, and the original active port transits to the blocked state.
As shown in
form another, with Port 1 being active and Port 2 being standby.
Primary/secondary port
Primary port and secondary port are two port types in a smart link group. When both ports in a smart
link group are up, the primary port preferentially transits to the forwarding state, and the secondary
port stays in standby state. Once the primary port fails, the secondary port takes over to forward
traffic. As shown in
ports, and Port 2 of Device C and that of Device D secondary ports.
Primary/secondary link
The link that connects the primary port in a smart link group is the primary link; the link that connects
the secondary port is the secondary link.
Flush message
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.
Protected VLAN
A smart link group controls the forwarding state of protected VLANs. Each smart link group on a port
controls a different protected VLAN. 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
control VLAN.
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
process flush messages in the receive control VLAN and refresh their MAC address forwarding
entries and ARP/ND entries.

How Smart Link works

Link backup
As shown in
C is the secondary link. Typically, Port 1 is in forwarding state, and Port 2 is in standby state. When
the primary link fails, Port 2 takes over to forward traffic and Port 1 is blocked and placed in standby
state.
When a port switches to the forwarding state, the system outputs log information to notify the user of
the port state change.
Figure 23, Port 1 and Port 2 of Device C form a smart link group and those of Device D
Figure 23, you can configure Port 1 of Device C and that of Device D as primary
Figure 23, the link on Port 1 of Device C is the primary link. The link on Port 2 of Device
Figure 23) send flush messages within the transmit
90
Figure 23) receive and