NSX-T requirements impact both physical and virtual networks.

Physical Network Requirements

Physical requirements determine the MTU size for networks that carry overlay traffic, dynamic routing support, time synchronization through an NTP server, and forward and reverse DNS resolution.



Provide an MTU size of 1600 or greater on any network that carries Geneve overlay traffic must.

Geneve packets cannot be fragmented. The MTU size must be large enough to support extra encapsulation overhead.

This design uses an MTU size of 9000 for Geneve traffic. See Jumbo Frames Design Decisions.

Enable dynamic routing support on the upstream Layer 3 devices.

You use BGP on the upstream Layer 3 devices to establish routing adjacency with the Tier-0 SRs.

Provide an NTP server.

The NSX-T Manager requires NTP settings that synchronize it with the rest of the environment.

Establish forward and reverse DNS resolution for all management VMs.

The NSX-T Controllers do not require DNS entries.

NSX-T Component Specifications

When you size the resources for NSX-T components, consider the compute and storage requirements for each component, and the number of nodes per component type.

Size of NSX Edge services gateways might be different according to tenant requirements. Consider all options in such a case.

Table 1. Resource Specification of the NSX-T Components

Virtual Machine


Memory (GB)

Storage (GB)

Quantity per NSX-T Deployment

NSX-T Manager

12 (Large)

48 (Large)

200 (Large)


NSX-T Edge virtual machine

2 (Small)

4 (Small)

120 (Small)

Numbers are different according to the use case. At least two edge devices are required to enable ECMP routing.

4 (Medium)

8 (Medium)

120 (Medium)

8 (Large)

16 (Large)

120 (Large)

Table 2. Design Decisions on Sizing the NSX-T Edge Virtual Machines

Decision ID

Design Decision

Design Justification

Design Implications


Use large-size NSX Edge virtual machines.

The large-size appliance provides all the performance characteristics if a failure occurs.