Dell S4820T Configuration Manual page 1009

The unit IDs are used for internal system operations.
To explicitly configure the default values on each peer switch, use the unit-id command.
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 enhanced 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 in
the Enabling VLT and Creating a VLT
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 eVLT 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.
Virtual Link Trunking (VLT)
Domain.
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