Objectives
The simulator ticks each one as soon as the network meets it.
Add tenant T1: Vrf-T1, L3 VNI 50001, VLAN 3001.
Add VLAN 10 (VNI 10010, gateway 192.168.10.254/24) and VLAN 20 (VNI 10020, gateway 192.168.20.254/24) in T1, on all leaves.
Change PHY1 to carry VLANs 10 and 100, and put L4 port 7 in VLAN 20.
Deploy again.
Ping PC4 (192.168.20.40) from PC2, routed across the fabric.
Before you start
Deploying is safe to repeat, because a line a switch already has changes nothing. A controller makes a change consistent across leaves, and that is the point: every gateway is the same on every leaf without you typing it four times.
Concept
A fabric controller: intent to configuration
A controller holds what you want: spines, leaf pairs, tenants, networks. It works out each switch’s lines from that intent and the cabling. Change the intent once, and every switch follows. Because it knows what each switch should have, it can also find drift: a change made directly on a switch.
Concept
A leaf-spine fabric on Dell switches
Every leaf connects to every spine, and no leaf connects to another leaf, so any two leaves are two hops apart over several equal paths. eBGP routes between loopbacks form the underlay, usually with one ASN per leaf pair. EVPN then runs on the same BGP sessions: VTEPs announce their VNIs and hosts, and tunnels form from those routes. SONiC can peer without link addresses: ipv6 enable and neighbor interface are enough.
