With NSX Federation, you can deploy a tier-1 gateway to provide distributed routing only, or you can configure services on it.
Tier-1 Gateway for Distributed Routing Only
You can create a tier-1 gateway in NSX Federation for distributed routing only. This gateway has the same span as the tier-0 gateway it is linked to. The tier-1 does not use Edge nodes for routing. All traffic is routed from host transport nodes to the tier-0 gateway. However, to enable cross-location forwarding, the tier-1 allocates two Edge nodes from the Edge cluster configured on the linked tier-0 to use for that traffic.
Tier-1 Gateway with Services or Custom Span
- You want to run services on the tier-1 gateway.
- You want to deploy a tier-1 gateway that has a different span than the linked tier-0 gateway.
You can remove locations, but you cannot add locations that are not already included the span of the tier-0 gateway.
You select one of the locations to be the primary location. All other locations are secondary. The HA mode for the tier-1 gateway is Active Standby. All traffic passing through this tier-1 gateway passes through the active edge node in the primary location.
If both the tier-1 gateway and the linked tier-0 gateway have primary and secondary locations, configure the same location to be primary for both gateways to reduce cross-location traffic.