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7. When you create a VLT domain on a switch, the system automatically assigns a unique unit ID (0 or 1) to each peer switch.
The unit IDs are used for internal system operations.
VLT DOMAIN CONFIGURATION mode
unit-id {0 | 1}
Use the unit-id command to explicitly configure the default values on each peer switch.
You must configure a different unit ID (0 or 1) on each peer switch.
Use this command to minimize the time required for the VLT system to determine the unit ID assigned to each peer switch
when one peer switch reboots.
8. Configure multi-domain VLT. Configure the port channel to be used for the VLT interconnect on a VLT switch and enter
interface configuration mode.
CONFIGURATION mode
interface port-channel id-number
Enter the same port-channel number configured with the peer-link port-channel command.
9. Place the interface in Layer 2 mode.
INTERFACE PORT-CHANNEL mode
switchport
10. Associate the port channel to the corresponding port channel in the VLT peer for the VLT connection to an attached device.
INTERFACE PORT-CHANNEL mode
vlt-peer-lag port-channel id-number
Valid port-channel ID numbers are from 1 to 128.
11. Ensure that the port channel is active.
INTERFACE PORT-CHANNEL mode
no shutdown
12. Add links to the mVLT port. Configure a range of interfaces to bulk configure.
CONFIGURATION mode
interface range {port-channel id}
13. Enable LACP on the LAN port.
INTERFACE mode
port-channel-protocol lacp
14. Configure the LACP port channel mode.
INTERFACE mode
port-channel number mode [active]
15. Ensure that the interface is active.
MANAGEMENT INTERFACE mode
no shutdown
16. Repeat steps 1 through 15 for the VLT peer node in Domain 1.
17. Repeat steps 1 through 15 for the first VLT node in Domain 2.
18. Repeat steps 1 through 15 for the VLT peer node in Domain 2.
Verifying a VLT Configuration
To monitor the operation or verify the configuration of a VLT domain, use any of the following show commands on the primary
and secondary VLT switches.
Display information on backup link operation.
EXEC mode
show vlt backup-link
Display general status information about VLT domains currently configured on the switch.
EXEC mode
show vlt brief
Virtual Link Trunking (VLT)
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