Configure port binding (for iSCSI traffic) on VMware vSphere 6.7 - VMware - Tutorials

On VMware vSphere 6.7, you have the ability to use multiple paths to access your iSCSI storage (usually a NAS) even if the same subnet is used.
However, this will require configuring port binding for the iSCSI controller of your VMware ESXi host.

Here is a complete example with a VMware ESXi host having 2 network cards for iSCSI and an iSCSI server with a single network card for iSCSI.
The advantage being that if one of the network cards on your VMware ESXi host fails, the connection can still work via the other network card.

1. Configure your VMware ESXi host network

For this example, we added 2 physical network cards to our host for iSCSI storage access.
In this case, these are the network cards "vmnic1" and "vmnic2" which are not used at the moment.

1.1. Add the 1st VMkernel adapter for iSCSI

To get started, select your VMware ESXi host, go to “Configure -> VMkernel adapters” and click: Add Networking.

Note: as noted by VMware, you must create one VMkernel adapter per physical NIC to use.

In the "Add Networking" wizard that appears, select "VMkernel Network Adapter" and click Next.

To better separate iSCSI traffic from the rest of your host's network, we recommend creating a new virtual switch.
To do this, select “New standard switch” and click Next.

If you selected "New standard switch" in the previous step, you will need to choose the physical adapters to assign to this new standard virtual switch.
Click the "+" icon.

Select one of your new physical network cards and click OK.
Then click the "+" icon again and add the 2nd physical network card.

In our case, we will use the physical network cards: vmnic1 and vmnic2.

Specify "iSCSI Network 1" for the network label and click Next.

Preferably, you should use a different physical switch for the iSCSI network.
This avoids saturating the physical switch used in particular for managing your VMware ESXi host.

In our case, it is a simple physical switch and no DHCP server is therefore present on this network.
We will therefore use IP addresses on this network dedicated to iSCSI traffic.

For the 1st VMkernel adapter of this 1st host, we will use the IPv4 address "10.20.0.11" and the subnet mask "255.255.255.0".
Note that our host uses a network ID of "10.0.0.x" with a subnet mask of "255.255.255.0".
The 2 networks are therefore different.

A summary of your new networking appears.
Click Finish.

Your new VMkernel adapter "vmk1" appears, along with the network label (port group) "iSCSI Network 1", the virtual switch created "vSwitch1" and the IP address defined for this VMkernel adapter "10.20.0.11".

1.2. Add the 2nd VMkernel adapter for iSCSI

Click "Add Networking" again to add the second VMkernel adapter.

In the "Add Networking" wizard that appears, select "VMkernel Network Adapter" and click Next.

This time choose "Select an existing standard switch" and click "Browse".

Important : as noted by VMware, for iSCSI port bonding to work properly, it is important that your VMkernel adapters dedicated to iSCSI traffic are on the same virtual switch (vSwitch).

Select the virtual switch "vSwitch1" created previously when creating your 1st VMkernel adapter.

With the existing standard switch selected, click Next.

This time, specify "iSCSI Network 2" for the network label and click Next.

Select "Use static IPv4 settings" as before and specify the IPv4 address and subnet mask to use.
For the 2nd VMkernel adapter of this 1st host, we will use the IPv4 address "10.20.0.12" and the subnet mask "255.255.255.0".

A summary of the configuration of your 2nd VMkernel adapter appears.
Click Finish.

Your new VMkernel adapter appears.

If you want to access the same iSCSI storage from a second host, don't forget to add 2 physical network cards to it and configure these 2 new additional VMkernel adapters.

In our case, this gives this for our 2nd VMware ESXi host:

vmk1 / iSCSI Network 1 / vSwitch1 / 10.20.0.13
vmk2 / iSCSI Network 2 / vSwitch1 / 10.20.0.14