Reference Guide

Usage
Information
● After you configure a VLT domain on each peer switch and connect (cable) the two VLT peers on
each side of the VLT interconnect, the system elects a primary and secondary VLT peer device. To
configure the primary and secondary roles before the election process, use the primary-priority
command. Enter a lower value on the primary peer and a higher value on the secondary peer. If the
primary peer fails, the secondary peer (with the higher priority) takes the primary role. If the primary
peer (with the lower priority) later comes back online, it is assigned the secondary role (there is no
preemption).
● If the priority values configured on the two VLT peers are equal, VLT uses the default primary election
mechanism based on the values of the system MAC addresses of the two nodes. The VLT peer with
the lowest system MAC address assumes the primary role.
● In a scenario where the heartbeat is up and the VLTi link goes down between the VLT peers, both the
VLT peers retain their primary and secondary roles. However, the VLT LAG on the secondary VLT peer
is shutdown.
NOTE: When you configure priority for VLT peers using this command, the configuration is not
effective immediately. This primary priority configuration comes into effect the next time election is
triggered.
Example
OS10(conf-vlt-1)#primary-priority 2
Supported
Releases
10.4.1.0 or later
show spanning-tree virtual-interface
Displays details of STP and RPVST+ information specific to VLT.
Syntax
show spanning-tree virtual-interface [detail]
Parameters detail — (Optional) Displays detailed output.
Default Not configured
Command Mode EXEC
Usage
Information
None
Example
OS10# show spanning-tree virtual-interface
VFP(VirtualFabricPort) of RSTP 1 is Designated Forwarding
Edge port: No (default)
Link type: point-to-point (auto)
Boundary: No, Bpdu-filter: Disable, Bpdu-Guard: Disable, Shutdown-on-Bpdu-Guard-violation: No
Root-Guard: Disable, Loop-Guard: Disable
Bpdus (MRecords) Sent: 11, Received: 7
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
---------------------------------------------------------------------------------------------
VFP(VirtualFabricPort) 0.1 0 1 FWD 0 32768 0078.7614.6062 0.1
OS10# show spanning-tree virtual-interface
VFP(VirtualFabricPort) of vlan 100 is Designated Blocking
Edge port: No (default)
Link type: point-to-point (auto)
Boundary: No, Bpdu-filter: Disable, Bpdu-Guard: Disable, Shutdown-on-Bpdu-Guard-violation: No
Root-Guard: Disable, Loop-Guard: Disable
Bpdus (MRecords) Sent: 7, Received: 9
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
---------------------------------------------------------------------------------------------
VFP(VirtualFabricPort) 0.1 0 1 BLK 0 4196 90b1.1cf4.a602 0.1
Example (detail)
OS10# show spanning-tree virtual-interface detail
Port 1 (VFP(VirtualFabricPort)) of RSTP 1 is designated Forwarding
Port path cost 1, Port priority 0, Port Identifier 0.1
Designated root priority: 32768, address: 00:78:76:14:60:62
Designated bridge priority: 32768, address: 00:78:76:14:60:62
698 Virtual Link Trunking