About the Fabric Default Parameters

The following is a list of NetVisor default port numbers, multicast addresses, and communication information about the fabric:

Internal keepalive message

  • Multicast IP:
  • UDP Destination Port: 23399
  • NetVisor sends the packet from the CPU to the internal port to ensure that the CPU path to the switch is working and the internal port is up.

Fabric keepalive message

  • UDP Destination Port: 23394
  • Point to point UDP fabric keepalives: if NetVisor cannot receive these messages, the fabric node may go into an offline state.

Global discovery message

  • Multicast IP:
  • UDP destination port: 23399
  • Each node periodically multi-casts a message about the fabric. This enables the fabric-show command on directly connected nodes, Layer 2-adjacent, to display available fabric instances and also enables the fabric-join name name-string command.

Proxy commands

  • TCP Destination Port: 23397 SSL
  • Used for NetVisor OS-to-NetVisor OS communication. Used for internal purposes and also to implement commands executed on other switches from a local switch.

Status propagation

  • TCP Destination Port: 23398 SSL
  • Port changes and vport changes propagated to other nodes in the fabric.

TCP API clients

  • TCP Destination Port: 23396 SSL
  • API clients connect to this port. Disable using the admin-service-modify if <mgmt/data> no-net-api command.

File System replication

  • TCP Destination Port: 23392 SSL
  • For ZFS send and ZFS receive messages when replicating file systems across the fabric.

L2 ARP/DMAC miss/Broadcast encapsulation

  • UDP Destination Port: 23389
  • These are special VXLAN-encapsulated packets sent from one management CPU to another management CPU between two Layer 2 adjacent switches.

L3 ARP/DMAC miss/Broadcast encapsulation

  • UDP Destination Port: 23388
  • These are special VXLAN-encapsulated packets sent from one management CPU to another management CPU between two switches interconnected at Layer 3.

vPORT status

  • Multicast IP:
  • UDP Destination Port: 23390
  • vPort update messages associated to status changes to hypervisors or hosts in the fabric.

vFlow CPU packets

  • UDP Destination Port: 23398
  • These packets are sent point-to-point for vflow-snoop of a fabric-scoped vFlow

Note:  All of these messages must not drop or become lost in order to keep a fabric healthy. However, the multicast messages do not propagate through routers and therefore NetVisor OS does not rely on them for fabrics created over Layer 3 networks.

The fabric-node-show command displays information about internal data structures for each node in the fabric, including the node state.

For example:

CLI (network-admin@switch) > fabric-node-show

fab-name   mgmt-ip       in-band-ip  in-band-vlan-type fab-tid  version          state

-------- -------------- ----------- ----------------- ------- --------------     ------

WDTest   public            7       5.0.0-5000014540  online


If NetVisor OS does not receive any keepalives or other messages from a fabric node for about 30 seconds, then NetVisor marks the node as offline.

Anything that prevents keepalives or other kinds of messages from flowing freely between fabric nodes can cause problems for fabric connectivity.