Loopback addresses are configured on leaf and spine switches for use as router IDs and VTEP addresses. Autonomous System Numbers (ASNs) are configured on the switches for use with Border Gateway Protocol (BGP).
Each leaf or spine switch must have a unique router ID. Each leaf pair shares a VTEP IP address, and an ASN. Spines do not have VTEP addresses, and all spines in the fabric share the same ASN. The external switches are also configured for BGP in this example. They each have unique router IDs and share an ASN that is different from the leaf and spine ASNs.
The values that are used in this deployment example are listed in the table below.
Switch | Router ID (Loopback 0) | VTEP address (Loopback 1) | ASN |
Leaf 1A | 10.1.1.1/32 | 10.0.0.1/32 | 65101 |
Leaf 1B | 10.1.1.2/32 | 10.0.0.1/32 | 65101 |
Leaf 2A | 10.1.1.3/32 | 10.0.0.2/32 | 65102 |
Leaf 2B | 10.1.1.4/32 | 10.0.0.2/32 | 65102 |
Leaf 3A | 10.1.1.5/32 | 10.0.0.3/32 | 65103 |
Leaf 3B | 10.1.1.6/32 | 10.0.0.3/32 | 65103 |
Leaf 4A | 10.1.1.7/32 | 10.0.0.4/32 | 65104 |
Leaf 4B | 10.1.1.8/32 | 10.0.0.4/32 | 65104 |
Spine 1 | 10.2.2.1/32 | N/A | 65200 |
Spine 2 | 10.2.2.2/32 | N/A | 65200 |
Spine 3 | 10.2.2.3/32 | N/A | 65200 |
Spine 4 | 10.2.2.4/32 | N/A | 65200 |
External A | 10.3.0.1/32 | N/A | 65300 |
External B | 10.3.0.2/32 | N/A | 65300 |