Deployment Guide

Conguring the Commands without a Separate User
Account
Starting with Dell Networking OS version 9.3(0.0), you can congure the PMUX mode CLI commands without having to congure a new,
separate user prole. The user prole you dened to access and log in to the switch is sucient to congure the PMUX mode commands.
The IOA PMUX Mode CLI Commands section lists the PMUX mode CLI commands that you can now congure without a separate user
account.
Virtual Link Trunking (VLT)
VLT allows physical links between two chassis to appear as a single virtual link to the network core. VLT eliminates the requirement for
Spanning Tree protocols by allowing link aggregation group (LAG) terminations on two separate distribution or core switches, and by
supporting a loop-free topology. VLT provides Layer 2 multipathing, creating redundancy through increased bandwidth and enabling multiple
parallel paths between nodes and load-balancing trac where alternative paths exist.
NOTE: When you launch the VLT link, the VLT peer-ship is not established if any of the following is TRUE:
• The VLT System-MAC congured on both the VLT peers do not match.
• The VLT Unit-Id congured on both the VLT peers are identical.
• The VLT System-MAC or Unit-Id is congured only on one of the VLT peers.
• The VLT domain ID is not the same on both peers.
If the VLT peer-ship is already established, changing the System-MAC or Unit-Id does not cause VLT peer-ship to go down.
Also, if the VLT peer-ship is already established and the VLT Unit-Id or System-MAC are congured on both peers, then changing the
CLI congurations on the VLT Unit-Id or System-MAC is rejected if any of the following become TRUE:
• After making the CLI conguration change, the VLT Unit-Id becomes identical on both peers.
• After making the CLI conguration change, the VLT System-MAC do not match on both peers.
When the VLT peer-ship is already established, you can remove the VLT Unit-Id or System-MAC conguration from either or both
peers. However, removing conguration settings can cause the VLT ports to go down if you congure the Unit-Id or System-MAC on
only one of the VLT peers.
Overview
VLT allows physical links between two chassis to appear as a single virtual link to the network core or other switches such as Edge, Access,
or top-of-rack (ToR).
VLT reduces the role of spanning tree protocols (STPs) by allowing link aggregation group (LAG) terminations on two separate distribution
or core switches, and by supporting a loop-free topology. (To prevent the initial loop that may occur prior to VLT being established, use a
spanning tree protocol.
VLT provides Layer 2 multipathing, creating redundancy through increased bandwidth, enabling multiple parallel paths between nodes and
load-balancing trac where alternative paths exist.
Virtual link trunking oers the following benets:
• Allows a single device to use a LAG across two upstream devices.
• Eliminates STP-blocked ports.
• Provides a loop-free topology.
• Uses all available uplink bandwidth.
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PMUX Mode of the IO Aggregator