Random Session Disconnects due to Spanning Tree Configuration

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August 2, 2018

Last modified: 12/09/2022, 2:31 am

Knowledge Base Article Troubleshooting Performance HP Anyware Remote Workstation Card Zero Clients

Scenario

PCoIP sessions experience random session disconnects of some or all clients. Re connection is not always possible straight away.

 

Cause

A Spanning Tree Protocol (STP) re-calculation can cause random session disconnects. STP will cause the network interface to not forward data during the initial phase of a re-calculation which can last from 30 to 50 seconds, unless the network interface has been configured for Portfast operation.  Portfast ensures that the network interface forwards data while the STP calculation is implemented. 

A STP recalculation can be triggered by the introduction of a new switch in the network environment including the introduction of new IP Phones, or a reboot on an IP Phone, since IP Phones incorporate a small network switch.

Note:

  • Without Portfast enabled on the network interface, a STP recalculation event longer than 30 seconds will cause the PCoIP Session to disconnect.
  • Cisco switches have two modes of portfast. Portfast and portfast switch. The later mode should be used with IP Phones.

 

Resolution

 

Virtual Desktop Best Practice

Portfast must be configured on all network interfaces that are connected to PCoIP end-points including:

  • PCoIP Zero Clients
  • PCoIP Host Cards
  • Software/Mobile client
  • HP Anyware Software

Consider configuring BPDU Filter on network interfaces that have been configured to enable Portfast. This will prevent the transmission of BPDU packets that are received on a Portfast enabled port.