A key decision is how the SmartFabric-based network will interconnect with the upstream network. All switches supported for SFS and supported qualified for VxRail include support for Layer 2 and Layer 3, including static routing and Border Gateway Protocol (BGP) for Layer 3. A single rack deployment supports either Layer 2 or Layer 3 from the leaf switches. A multi-rack deployment supports either Layer 2 or Layer 3 from the leaf switch layer, or Layer 3 from the spine switch layer.
If the uplinks from the SmartFabric switches are Layer 2:
- Connectivity options from the leaf switches upstream are either a static Link Aggregation Group (LAG) or Link Aggregation Control Protocol (LACP)
- Upstream switches can be VLT/vPC peers or individual Layer 3 switches. SmartFabric automatically creates single MLAG or individual LAGs to each uplink switch
- The boundary for the Layer 2 networks derived from the VxRail cluster is in the upstream data center network. Layer 3 routing services must be configured at this layer to enable connectivity for VxRail networks that require external access
If the uplinks from the SmartFabric switches are Layer 3:
- Point-to-point links are required between the SmartFabric switches with the Layer 3 uplinks and the upstream switches
- Connectivity options from the leaf switches or spine switches upstream are static routing or BGP
- For static routing
- Next-hop static routing statements must be configured on the upstream network for the Layer 3 networks passed upstream from the SmartFabric network
- SmartFabric switches must peer with upstream switches running eBGP
- The point-to-point links must include the ASN value dependent on whether the uplinks are derived from the leaf switches or spine switches
- A default ASN value is set at the spine layer and the leaf layer at the time of SFS enablement. These values can be modified before deploying the VxRail cluster on the switch fabric
- SmartFabric networks support both Layer 3 routing per interface or Layer 3 routing per VLAN
- The SmartFabric switches will run Rapid Per-VLAN Spanning Tree (RPVST+) if the Layer 3 routing per VLAN option is enabled
For any SmartFabric-enabled network for VxRail, the user interface connected with the master switch is used to configure the uplinks to the upstream network.