Ephemeral port user on VMware Photon OS and Appliances

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides information on the use of Ephemeral ports in VMware Photon and Appliance (VMware vCenter, Platform Services Control, Site Recovery Manager for example) for short-lived transport.

Resolution

This article contains a port range and commands specific to the Photon OS, the use of ephemeral ports is valid for any OS (Windows or Linux). The Ephemeral Port range can and will vary by OS, but the use of the port(s) will still be deemed critical and necessary for the proper operation of the VMware product/application/service.  For other Operating Systems, please refer to that OS for specifics on the default port range and method to document/validate the Ephemeral Port range in use by the OS.

The Photon OS leverages ports (TCP, UDP and SCTP) between 32768 and 60999 as Ephemeral Ports. The OS assigns these ports on a temporary basis and will remain live only for the length of the communication session. After completion, the port(s) is released and is available to the OS to re-use.

This port assignment is OS controlled and ephemeral ports are deemed critical and necessary for the proper operation of the product/application/service. These ports will not be listed in the documentation.

The port range can be verified with one of these commands commands:

• cat /proc/sys/net/ipv4/ip_local_port_range

Example output:

32768      60999

 

• sysctl – a | grep ip_local_port_range

Example output:

net.ipv4.ip_local_port_range = 32768      60999