Users Guide

Description Behavior at Peer Up Behavior During Run
Time
Action to Take
information, refer to the
Release Notes for this
release.
VLT LAG ID is not
configured on one VLT
peer
A syslog error message is
generated. The peer with
the VLT configured
remains active.
A syslog error message is
generated. The peer with
the VLT configured
remains active.
Verify the VLT LAG ID is
configured correctly on
both VLT peers.
VLT LAG ID mismatch
The VLT port channel is
brought down.
A syslog error message is
generated.
The VLT port channel is
brought down.
A syslog error message is
generated.
Perform a mismatch
check after the VLT peer
is established.
Reconfiguring Stacked Switches as VLT
To convert switches that have been stacked to VLT peers, use the following procedure.
1 Remove the current configuration from the switches. You will need to split the configuration up for each
switch.
2 Copy the files to the flash memory of the appropriate switch.
3 Copy the files on the flash drive to the startup-config.
4 Reset the stacking ports to user ports for both switches.
5 Reload the stack and confirm the new configurations have been applied.
6 On the Secondary switch (stack-unit 2), enter the command stack-unit 2 renumber 1.
7 Confirm the reload query.
8 After reloading, confirm that VLT is enabled.
9 Confirm that the management ports are interconnected or connected to a switch that can transfer
Heartbeat information.
Specifying VLT Nodes in a PVLAN
You can configure VLT peer nodes in a private VLAN (PVLAN). VLT enables redundancy without the
implementation of Spanning Tree Protocol (STP), and provides a loop-free network with optimal bandwidth
utilization.
Because the VLT LAG interfaces are terminated on two different nodes, PVLAN configuration of VLT VLANs
and VLT LAGs are symmetrical and identical on both the VLT peers. PVLANs provide Layer 2 isolation between
ports within the same VLAN. A PVLAN partitions a traditional VLAN into sub-domains identified by a primary
and secondary VLAN pair. With VLT being a Layer 2 redundancy mechanism, support for configuration of VLT
nodes in a PVLAN enables Layer 2 security functionalities. To achieve maximum VLT resiliency, you should
configure the PVLAN IDs and mappings to be identical on both the VLT peer nodes.
Virtual Link Trunking (VLT) 1067