We all knew this day would come: There are no more IPv4 addresses available for public assignment. The next version of the Internet Protocol, IPv6, allows for many more address assignments and further simplifies networking. Find out whether you need to implement IPv6 in your VMware environment, and if so, learn how to enable it for smoother ESXi networking.
Do you need IPv6?
In the near future, end users will have IPv6-only devices from tablets to phones to computers. But your VMware ESXi infrastructure may be based on IPv4. At the same time, the infrastructure may have certain virtual machines (VMs) -- such as those that are accessed by the public, like Web servers or mail servers -- that run best with IPv6. So where do you start?
If you already have VMs that use IPv6, it’s a good idea to configure IPv6 on the ESXi hosts as well. If you want IPv6, it's good to use it on all VMs and hosts. Most VMs and physical hosts will be on the same network anyway, so it simplifies ESXi networking and keeps everything updated.
On the other hand, end users of the VMware ESXi infrastructure don't directly connect to the hosts, and even the administrator doesn't do that very frequently, so configuring IPv6 on ESXi hosts may not be necessary. If you use vCenter Server for management tasks, you can configure IPv6 on vCenter instead of the ESXi hosts. The only time it’s absolutely necessary to configure IPv6 on ESXi hosts is if you’re using the vSphere Client to directly connect with and manage hosts from an IPv6-only device.
Enabling IPv6 on VMware ESXi
By default, IPv6 is disabled for the management VMkernel port (the network used to manage ESXi), so you have to enable it manually. When you select the IPv6 Configuration option from the Configure Network screen on the VMware ESXi host, you can select Enable IPv6. Since IPv6 uses automatic configuration, it will detect the information it needs to connect to the rest of the network.
IPv6 is based off the Neighbor Discovery Protocol, which means it will detect other IPv6 nodes in the network automatically and learn from them which network address to use. Once that’s done, the host adds its own MAC address to the network address and you're ready to go with IPv6.
Assigning IPv6 addresses to ESXi hosts
Assigning an IPv6 address automatically is easy, but managing it is not so simple. To ease ESXi networking administration, you might be better off configuring the IPv6 address manually. That way, you'll choose the IP address node bit yourself, which makes it easier to remember.
It’s a good idea to enter the IPv6 address and gateway address manually. First, you'll need to find out what network address your infrastructure uses. Within that range, specify the node address you want to assign. The resulting address will look like 2ef0:1984:ab45:3c12::3, where to the left of the double colon (::) is the network address, and to the right is where you manually specify the node address (in this case, 3). Now press Enter to save the changes and your VMware ESXi host is ready to start using IPv6.
This was first published in December 2011