No network connectivity if all ports are in use

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• The virtual machines lose network connection after vMotion.
• After several successful vMotion migrations to the same host, many of the virtual machines lose network connectivity.
• Connect is not selected for the virtual machine's VMNIC. Reselecting Connect restores network connectivity.
• The Event log and Events in VirtualCenter show the error:
  
  Failed to initialize ethernet0
  
  
• In the vmware.log file in the virtual machines that lost connectivity, you see the error:
  
  [msg.ethernet.openFailed] Failed to initialize ethernet0
  
  
• In the VMkernel log on the host to which virtual machines were migrated, you see the error:
  
  Can't connect device: `port group name`: Out of resources

Environment

VMware VirtualCenter 2.5.x
VMware vCenter Server 5.1.x
VMware vCenter Server 5.5.x
VMware ESXi 3.5.x Installable
VMware ESXi 4.1.x Installable
VMware ESX Server 3.5.x
VMware vSphere ESXi 5.0
VMware ESXi 4.0.x Installable
VMware ESXi 3.5.x Embedded
VMware vSphere ESXi 6.0
VMware ESX 4.0.x
VMware ESXi 4.0.x Embedded
VMware vCenter Server 4.0.x
VMware vCenter Server 5.0.x
VMware ESXi 4.1.x Embedded
VMware vSphere ESXi 5.5
VMware vCenter Server 4.1.x
VMware ESX 4.1.x
VMware vSphere ESXi 5.1
VMware vCenter Server 6.0.x

Resolution

You may experience this issue if the virtual switch has exceeded its number of configured VMkernel ports.

For example, if you have a single virtual switch (that is set to the default of 24 ports for VMware Infrastructure 3, 56 default ports in vSphere) with multiple port groups and virtual machines, but the output of the esxcfg-vswitch command shows that the virtual switch has 32 configured ports and 32 ports in use, the virtual switch has exceeded its number of configured ports.

Note: Virtual switches have overhead ports that show up in the output of the esxcfg-vswitch -l command. For more information, see Reserved or overhead ports for virtual switches (1008040). Each virtual network adapter in a virtual machine connected to the vSwitch, each port group, and each NIC uplink uses one port. The additional overhead is allocated regardless of the number of ports on the virtual switch.

There are several possible resolutions. To resolve this issue, either:

• Increase the number of ports for the virtual switch and reboot the host for the changes to take effect.
  
  Note: VMware recommends that you increase the number of ports for all hosts in a DRS cluster to prevent this issue from occurring on another host.
  
  
• Create a new virtual switch and spread the virtual machines and port groups across the two switches.
• If using NIC teaming, ensure that the load balancing policy on all the ESXi/ESX hosts in the cluster is the same.
• If VLAN is configured, ensure that VLAN is present on all the ESXi/ESX hosts in the cluster.
• Ensure that Notify Switches under NIC teaming is set to Yes.

For related information, see Change the Number of Ports for a vSwitch in the vSphere Online Library.

Additional Information

For translated versions of this article, see:

• 日本語: すべてのポートが使用中である場合にネットワーク接続がない (2081928)
  
• 简体中文: 所有端口都在使用时无网络连接 (2087420)