VMware NSX-T : Basics about Gateway Router and Segment/Logical Switch
Earlier we talked about the Gateway Firewall in VMware NSX-T environment, Now we are going to discuss about the Gateway Router, Segment and Logical Switch in VMware NSX-T 2.5.
Gateway Router
NSX-T routing entity that provides distributed East-West routing. A gateway router also links a Tier-1 router with a Tier-0 router.
Logical Router Port
Logical network port which can attach to either a logical switch segment port or a physical network uplink port. Logical Router Ports are also used to connect the LR to SR services such as Network Address Translation (NAT), Load Balancing, Gateway Firewall, VPN etc.
Fig 1.1- Logical router components |
Tier-0 (T0) Logical Router
Provider gateway router is also known as Tier-0 gateway router, and interfaces with the physical network. Tier-0 gateway router is a top-tier router and can be configured as an active-active or active-standby cluster of service routers.
The gateway router runs BGP and peers with physical routers via the service router. In active-standby mode, the gateway router can also provide stateful services.
Fig 1.2- Tier 0 Logical router in VMware NSX-T |
Tier-1 (T1) Gateway Router
Tier-1 gateway router is the second tier router that connects to one Tier-0 gateway router for northbound connectivity, and one or more overlay networks for southbound connectivity.
Tier-1 gateway router can also be configured in an active-standby cluster of services when the router is configured to provide stateful services.
Segment / Logical Switch
Segments, called logical switches in previous versions of NSX, are API entities that provide virtual Layer 2 switching for both VM and router interfaces.
A segment gives tenant network administrators the logical equivalent of a physical Layer 2 switch, allowing a group of VMs to communicate on a common broadcast domain.
A segment is a logical entity that exists independent of the underlying infrastructure and spans many hypervisors. It provides network connectivity to VMs regardless of their physical location, allowing them to migrate between locations without requiring any reconfiguration.
Logical Switch Port
Logical switch attachment point to establish a connection to a virtual machine network interface or a logical router interface. The logical switch port reports applied switching profile, port state, and link status.