Concept Guide
Figure 130. Virtual Link Trunking
Multi-domain VLT
A multi-domain VLT (mVLT) conguration creates a port channel between two VLT domains by allowing two dierent VLT domains, using
dierent VLT Domain ID numbers, connected by a standard LACP LAG to form a loop-free Layer 2 topology in the aggregation layer.
This conguration supports a maximum of four (4) nodes per mVLT domain, increasing the number of available ports and allowing for dual
redundancy of the VLT.
Additionally, a VLT domain that is a member of one mVLT can be used in another mVLT conguration with a dierent VLT domain. Routing
protocols such as OSPF are not compatible with mVLT; however, VLT domains can be used for routing. A separate Layer 3 router is not
required for inter-VLAN communication.
The following gure shows how the core/aggregation port density in the Layer 2 topology is increased using mVLT. For inter-VLAN routing
and other Layer 3 routing, a separate Layer 3 router is required.
Virtual Link Trunking (VLT)
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