SFS uplink options to external network switches include:

• L2 uplinks from a leaf pair
• L3 uplinks from a leaf pair
• L3 uplinks from spines

The L2 uplink configuration requires fewer steps than the L3 uplink configuration. Consider choosing the L2 uplink configuration if you have no preference for an uplink type for a leaf pair. Uplinks from spines must be L3.

Note: As a best practice, use uplinks from a leaf pair. The leaves are referred to as border leaves. Connect VxRail nodes and other servers in the rack to border leaves in the same manner as other leaves in the SmartFabric.

L2 uplink planning

If you use an L2 uplink, determine the VLAN ID to use for VxRail external management and whether ports in the uplink are to be tagged or untagged. Typically, the VLAN is the same VLAN that is used for DNS and NTP services on the existing network. Optionally, you can route traffic from the external switch to the DNS/NTP servers.

The L2 uplink can be a Link Aggregation Control Protocol (LACP) or a static link aggregation (LAG) uplink. If L2 uplinks connect to a pair of PowerSwitch systems, Dell Technologies recommends using LACP with VLT.

For information about L2 uplink configuration, see the documentation in References.

Note: With L2 uplinks, all routing into and out of the SmartFabric is performed on external switches.

L3 uplink planning

SFS supports using L3 routed or L3 VLAN uplinks.

With L3 routed uplinks, each physical link is a point-to-point IP network. With an L3 VLAN, all uplinks are in a LAG, and an IP address is assigned to the VLAN containing the LAG. This validation guide provides examples using L3 routed uplinks. L3 VLAN examples are beyond the scope of the guide.

Point-to-point IP networks and addresses must be planned for each physical link in the L3 uplink.

Each leaf switch in the SmartFabric needs an IP address on the external management VLAN. An anycast gateway address on the same VLAN is also specified. This gateway address is the virtual router/anycast gateway address that is shared by all leaves in the SmartFabric,.

SmartFabric supports routing using external Border Gateway Protocol or static routes. This validation guide provides external Border Gateway Protocol and static routing examples. 

Note: SFS does not support other routing protocols.

If you are using external BGP, you must determine autonomous system numbers (ASNs) and router IDs for the external switches. These identifiers are automatically configured on all switches in the SmartFabric.

Note: SFS uses ASN 65011 for leaves and ASN 65012 for spines. If these ASNs conflict with your environment, you can change them in the SFS UI under 5. Edit Default Fabric Settings.

For information about the L3 uplink configuration, see the relevant documentation in References.