HP 5500 Ei 5500 Si Switch Series Configuration Guide

 98 
•  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 and the slave ports. At a time, only one 
port is active for forwarding, and the other port is blocked and in standby state.  When link failure occurs 
on the active port due to port shutdown or presence  of unidirectional link for example, the standby port 
becomes active to take over and the original  active port...

 99 
How Smart Link works 
Link backup mechanism 
As shown in Figure 24, the link on Port1 of Device C is the master link, and the link on Port2 of Device 
C is the slave link. Typically, Port1 is in forwarding  state, and Port2 is in standby state. When the master 
link fails, Port2 takes over to forward traffic an d Port1 is blocked and placed in standby state.  
 
 NOTE:  
When a port switches to the forwarding state, the system outputs log information to notify the user of the
port state change....

 100 
function to monitor the uplink ports of the upstream devices. Monitor Link adapts the up/down state of 
downlink ports to the up/down state of  uplink ports, triggering Smart Link to perform link switchover on 
the downstream device. 
For more information about Monitor Link, see  Configuring Monitor Link.  
Collaboration between Smart Link and CC of CFD 
Smart Link cannot sense by itself when faults (for  example, unidirectional link, misconnected fibers, and 
packet loss) occur on the intermediate...

 101 
•  Disable the spanning tree feature and RRPP on the ports that you want to add to the smart link group, 
and make sure that the ports are not member port s of any aggregation group or service loopback 
group.  
 
  NOTE:  
A loop may occur on the network during the time when  the spanning tree feature is disabled but Smart Link
has not yet taken effect on a port.  
Configuring protected VLANs for a smart link group 
You can configure protected VLANs for a smart link group by referencing MSTIs....

 102 
Step Command Remarks 
8.  Configure protected VLANs 
for the smart link group.  protected-vlan reference-instance 
instance-id-list
  By default, no protected VLAN is 
configured for a smart link group. 
 
 
Configuring member ports for a smart link group 
You can configure member ports for a smart link group ei
ther in smart link group view or in interface view. 
The configurations made in these two views have the same effect.  
In smart link group view 
To configure member ports for a smart link...

 103 
Enabling the sending of flush messages 
The control VLAN configured for a smart link group must be different from that configured for any other 
smart link group.  
Make sure the configured control VLAN already exists, and assign the smart link group member ports to 
the control VLAN.  
The control VLAN of a smart link group should also be one of its protected VLANs. Do not remove the 
control VLAN. Otherwise, flush messages cannot be sent properly.  
To enable the sending of flush messages:...

 104 
Configuring an associated device 
Configuration prerequisites 
Disable the spanning tree feature on the associated device’s ports that connect to the member ports of 
the smart link group; otherwise, the ports will discard  flush messages when they are not in the forwarding 
state in case of a topology change. 
Enabling the receiving of flush messages 
You do not need to enable all ports on the associat ed devices to receive flush messages sent from the 
transmit control VLAN; you only need to...

 105 
Task Command Remarks 
Clear the statistics about flush 
messages.  reset smart-link statistics 
Available in user view 
 
Smart Link configuration examples 
Single smart link group configuration example 
Network requirements 
As shown in Figure 25 , Device C and Device D are smart link devices, and Device A, Device B, and 
Device E are associated devices. Traffic of VLANs 1 through 30 on Device C and Device D are dually 
uplinked to Device A.  
Configure Smart Link on Device C and Device D for dual...

 106 
[DeviceC-GigabitEthernet1/0/1] undo stp enable 
[DeviceC-GigabitEthernet1/0/1] port link-type trunk 
[DeviceC-GigabitEthernet1/0/1] port trunk permit vlan 1 to 30 
[DeviceC-GigabitEthernet1/0/1] quit 
[DeviceC] interface gigabitethernet 1/0/2 
[DeviceC-GigabitEthernet1/0/2] shutdown 
[DeviceC-GigabitEthernet1/0/2] undo stp enable 
[DeviceC-GigabitEthernet1/0/2] port link-type trunk 
[DeviceC-GigabitEthernet1/0/2] port trunk permit vlan 1 to 30 
[DeviceC-GigabitEthernet1/0/2] quit 
# Create smart...

 107 
[DeviceD-GigabitEthernet1/0/2] shutdown 
[DeviceD-GigabitEthernet1/0/2] undo stp enable 
[DeviceD-GigabitEthernet1/0/2] port link-type trunk 
[DeviceD-GigabitEthernet1/0/2] port trunk permit vlan 1 to 30 
[DeviceD-GigabitEthernet1/0/2] quit 
# Create smart link group 1, and configure all VLANs mapped to MSTI 1 as the protected VLANs. 
[DeviceD] smart-link group 1 
[DeviceD-smlk-group1] protected-vlan reference-instance 1 
# Configure GigabitEthernet 1/0/1 as the master  port and GigabitEthernet...