ACI Fabric Discovery

Posted: 3 months ago

Fabric Discovery Workflow:- 

1.Connect to the KVM console of the first APIC and
complete the setup script by putting values such as fabric name, APIC cluster
size and TEP (tunnel endpoint) address pool.
2.Once above step is done, APIC 1 will start sending LLDP
via its fabric ports. The LLDP packets contain special TLVs having infra VLAN
information and its role as an APIC.
3.Once LLDP packets received by Leaf switch from APIC 1,
the leaf will program the infra VLAN on all ports where an APIC is detected.
4.The leaf node will start sending DHCP discovers on the
now-known infra VLAN.
5.The next step is to login to the APIC GUI and register
the first leaf node in the Fabric Membership submenu.
6.Once the Node ID is assigned to the leaf node, APIC 1
will respond with an IP address from the TEP address pool and thus DHCP process
7.The registered leaf node relays DHCP discovers from
other directly connected spines which were discovered via LLDP to APIC 1.
8.These dynamically discovered spine switches will appear
in the Fabric Membership submenu and it needs to be registered them through
9.Once the spines nodes are registered, APIC 1 responds
with an IP address from the TEP pool and DHCP process completed for all these
10.Further spines relay DHCP discovers from all other leaf
nodes of the fabric.
11.Once all the connected leaf nodes are registered, APIC 1
responds with an IP address from the TEP pool address completing discovery for
all leaf nodes.
12.Once the leaf nodes connected to other APICs are
registered, the APIC cluster can be established via TCP communication among the
13.It must be ensured that basic setup dialogue has been
completed for the remaining APICs before performing above steps.
14.Once all above
steps done, confirm that All APICs have formed a cluster and are fully fit. If
this is the condition, fabric discovery is complete.