Terminology - HP A5120 EI Configuration Manual

Smart Link is a feature developed to address the slow convergence issue with STP. It provides link
redundancy as well as fast convergence in a dual uplink network, allowing the backup link to take over
quickly when the primary link fails. To sum up, Smart Link has the following features:
Dedicated to dual uplink networks

Subsecond convergence

Easy to configure


Terminology

Smart link group
A smart link group consists of only two member ports: the master port and the slave port. Only one port
at a time is active for forwarding; 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, taking over and the original active port transitions to the blocked state.
As shown in
link group, with Port1 being active and Port2 being standby.
Master port/slave port
Master port and slave port are two port roles in a smart link group. When both ports in a smart link
group are up, the master port preferentially transitions to the forwarding state, and the slave port stays in
the standby state. Once the master port fails, the slave port takes over to forward traffic. As shown in
23, you can configure Port1 of Device C and Port1 of Device D as master ports, and Port2 of
Figure
Device C and Port2 of Device D as slave ports.
Master link/slave link
The link that connects the master port in a smart link group is the master link. The link that connects the
slave port is the slave link.
Protected VLAN
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
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
messages in the receive control VLAN and refresh their MAC address forwarding entries and ARP/ND
entries.
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.
23, Port1 and Port2 of Device C and Port1 and Port2 of Device D each form a smart
Figure
23) broadcast flush messages within the transmit
Figure
Figure
89
23) receive and process flush