Troubleshooting vMotion network connectivity issues
Article ID: 321012
Updated On: 03-31-2025
Products
Issue/Introduction
vMotion of Virtual Machines fails when migrating between esxi hosts
Environment
vSphere ESXi 6.7
vSphere ESXi 7.x
vSphere ESXi 8.x
Resolution
Identify which vmknics are used for vMotion on both hosts.
Option 1 Using the vCenter Server User Interface (UI)
Notes: For more information, see Creating a VMkernel port and enabling vMotion on an ESXi/ESX host. For best practices, see the Networking Best Practices for vSphere vMotion.
Option 2 Using the ESXi command line
1. List the network interface with the following command:
esxcli network ip interface list
Sample output:
vmk0
Name: vmk0
MAC Address: ##:##:##:##:##:##
Enabled: true
Portset: vSwitch0
Portgroup: Management Network
Netstack Instance: defaultTcpipStack
VDS Name: N/A
VDS UUID: N/A
VDS Port: N/A
VDS Connection: -1
Opaque Network ID: N/A
Opaque Network Type: N/A
External ID: N/A
MTU: 1500
TSO MSS: 65535
RXDispQueue Size: 1
Port ID: 33554436
2. For each VMkernel adapter entry, run this command:
esxcli network ip interface tag get -i [VMkernel adapter name]
Example command:esxcli network ip interface tag get -i vmk0
Any adapters with tag value vMotion will be used for vMotion.
Sample vMotion VMKernel adapter value:
Tags: VMotion
3. Run diagnostic tools between source and destination vMotion VMkernel adapters
vmkping
vmkping uses a VMkernel’s TCP/IP stack to send ICMP traffic to a destination host.
Suppose you have source vMotion VMkernel adapter vmk0 with IP #.#.#.1, and destination vMotion VMkernel adapter vmk0 with IP #.#.#.2
From source ESXi host, run this command:vmkping -I vmk0 #.#.#.2
Similarly, from destination ESXi host, run this command:vmkping -I vmk0 #.#.#.1
If the vmotion is configured on vmotion tcp/ip stack, run the below command:
vmkping -I vmk0 #.#.#.1 -S vmotion
Note: After you create a VMkernel adapter on the vMotion TCP/IP stack, you can use only this stack for vMotion on this host. The VMkernel adapters on the default TCP/IP stack are deactivated for the vMotion service, see Testing VMkernel network connectivity with the vmkping command.
4. With long distance vMotion, the maximum supported RTT is 150 milliseconds.
5. The netcat utility can be used to verify connectivity on a specific remote port. To run netcat use the following command:
nc
Suppose you have source vMotion VMkernel adapter vmk0 with IP #.#.#.1, and destination vMotion VMkernel adapter vmk0 with IP #.#.#.2. Since vMotion listens on port 8000 of the vMotion VMkernel adapter, you need to verify if you can establish a connection to port 8000.
From source ESXi host, run this command:
nc -z #.#.#.2 8000
From destination ESXi host, run this command:
nc -z #.#.#.1 8000
Sample successful output:
Connection to #.#.#.2 8000 port [tcp/*] succeeded!
6. For more information on nc and troubleshooting specific tcp/ip port connectivity issues, see:
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