Objectives
The simulator ticks each one as soon as the network meets it.
Build a vPC to PHY1: vpc domain explicit 1 leaf 101 102, policy group VPC-GRP using AEP1, vpc VPC1 with that group, and port 1/4 of both leaves in it.
Build bridge domains BD100 and BD200 in V1, with flood on.
Create EPGs E100 and E200 using PHYS1, with static-path vpc VPC1 on VLANs 100 and 200.
PHY1 bundles both uplinks.
Ping PC3 (192.168.100.30) from PC1, and PC4 (192.168.200.40) from PC2. PC1 cannot reach PC4.
Before you start
An EPG on a trunk maps a tagged VLAN into the fabric, so the classic switch needs no changes. Without flood on, the fabric keeps that VLAN local and show faults says why. This model runs one EPG per bridge domain, the usual first step when moving a network in: one VLAN, one EPG, one bridge domain.
Concept
ACI: the physical domain chain
A VLAN works on a port only if a chain of policies allows it. The EPG names a physical domain, the domain names a VLAN pool that holds the VLAN, and the port’s policy group names an AEP attached to that domain. A break anywhere raises a fault that names it. A classic switch joins through this chain, on a port or a vPC.
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.
