Which component is primarily used for external routing in NSX-T?

The Tier-0 router is primarily used for external routing in NSX-T. Its main function is to interface with external networks and manage the flow of traffic between the virtual networking environment created by NSX-T and the outside world. It handles North-South traffic, which is the traffic entering and leaving the data center, as opposed to East-West traffic that typically occurs between virtual machines within the same data center.

The Tier-0 router supports features like Static Routing and Dynamic Routing protocols (such as BGP and OSPF), enabling it to effectively communicate with external routers and networks. This makes it a critical component for facilitating external connectivity and routing policies for the entire NSX-T environment.

While the Edge Node is part of the NSX infrastructure and provides various services including routing and load balancing, it is the Tier-0 router itself that is responsible for the external routing functions. The Tier-1 router mainly serves as an internal routing layer and connects with Tier-0 routers for accessing external networks, thus reinforcing the role of the Tier-0 router in this context. The Service Router and Tier-1 router serve different purposes within the architecture, such as managing East-West traffic or specific services, rather than functioning as the main interface for external routing.