The universal segment ID pool specifies a range for use when building logical network segments. Cross-vCenter NSX deployments use a unique universal segment ID Pool to ensure that the universal logical switches VXLAN network identifiers (VNIs) are consistent across all secondary NSX Managers.

About this task

The universal segment ID is defined once on the primary NSX Manager and then synced to all of the secondary NSX Managers. The universal segment ID range controls the number of universal logical switches that can be created. Note that the segment ID range must be unique across any NSX Manager that you plan use in a cross-vCenter NSX deployment. This example uses a high range to provide future scalability.


  1. In vCenter, navigate to Home > Networking & Security > Installation and select the Logical Network Preparation tab.
  2. Click Segment ID > Edit.
  3. Enter a range for universal segment IDs, such as 900000-909999.

    This will be the range of IDs used by Universal Logical Switches. The Universal Segment ID pool must be unique across any NSX Managers that will be used in a cross-vCenter NSX deployment.

  4. If any of your transport zones will use multicast or hybrid replication mode, check Enable Universal multicast addressing and type a universal multicast address or a range of universal multicast addresses.

    In a cross-vCenter NSX environment, if you select hybrid mode, you must ensure that the multicast address specified does not conflict with any other multicast addresses assigned on any NSX Manager in the environment.

    Having a range of multicast addresses spreads traffic across your network, prevents the overloading of a single multicast address, and better contains BUM replication. The recommended multicast address range starts at and excludes

    Do not use or as the multicast address range, because these networks are used for local subnet control, meaning that the physical switches flood all traffic that uses these addresses. For more information about unusable multicast addresses, see


Later, after you configure universal logical switches, each universal logical switch receives a universal segment ID from the pool.