Objectives
The simulator ticks each one as soon as the network meets it.
On L1 and L2, build port-channel 10 as a trunk carrying VLANs 100 and 200, and make it vlt-port-channel 10.
Add port 3 of L1 and of L2 to it with LACP.
PHY1 bundles both uplinks: both its links are active.
VLAN 100 reaches across the fabric: ping PC3 (192.168.100.30) from PC1.
VLAN 200 reaches across too, separate from VLAN 100: ping PC4 (192.168.200.30) from PC2, and PC1 cannot reach PC4.
Before you start
The physical domain sees one LACP partner, so nothing blocks and both links forward. A VLAN missing from the trunk on one switch of the pair is a type-1 style mismatch: show vlt 1 mismatch tells you. The classic switch knows nothing about VXLAN: the leaf maps its tagged VLAN to a VNI.
Concept
Physical domains: joining classic switches to a fabric
Most fabrics must reach racks that know nothing about VXLAN: classic switches and bare-metal servers on tagged VLANs. The fabric treats that network as a physical domain. A leaf pair presents one LACP partner, carries the tagged VLANs on a trunk, and maps each VLAN to a VNI, so a host on a classic switch reaches a host anywhere in the fabric. Only VLANs that are mapped cross, and each stays separate.
Concept
VLT and MCLAG: two switches, one LACP partner
A leaf pair joined by a peer link looks like one switch to the device below it. That device bundles one link to each leaf with ordinary LACP, so spanning tree blocks nothing and both links forward. Dell OS10 calls this VLT, and SONiC calls it MCLAG. In a VXLAN fabric, the pair also shares one VTEP address, so the rest of the fabric sees a single tunnel endpoint, and either leaf can take the tunnel.
