Welcome back to vSphere 8 in the real world. Now we're going to discuss additional features and troubleshooting for your network.
So traffic shaping.
Traffic shaping is one of those things that not a lot of people do because they kind of want to see their stuff just
run and not have interruptions and things like that.
You will see it in environments though where there's a lot of machines that are maybe like low priority.
They're not really worried about their performance and things like that. And maybe they are noisy on the network though, right?
They have a tendency to take up a lot more bandwidth than needed.
So they'll go ahead and put some traffic shaping on a port group for those really less important virtual machines
so that the more important virtual machines running will have, you know, higher levels of access, less impeded access to network resources.
But again, it's not something I see out there a lot.
You can set there an average bandwidth. So a VM is not saying average is not the max, obviously, right?
It's saying that VMs can can peak above that. They can even burst, right, to a certain level.
But those peaks and bursts have to average out to not above a certain amount.
So you can go and you can say that on a VM that you want the average to be less than, you know,
500, you know, megabits or 500 kilobits or some crazy thing like that, right?
And you can say what the maximum peak can be, what the maximum burst can be.
So a peak and a burst are different in that a peak is going to be a spike up and down and a burst will be sustained for a little bit longer.
But again, we have to average out to be within a certain average.
So you can't run a peak or a burst for very long because they'll start to exceed your average.
Once you start to hit that average, it's going to make it come back down to be at or below average until there's room for another peak or another burst.
All right, so that's your traffic shaping policy.
So MAC addresses, are you going to allow MAC address changes or not?
Most of the time in most environments, you don't want to allow MAC address changes.
Most of the time, MAC address changes are going to be managed by your vCenter.
And so I've seen environments and different environments with different hypervisors where you have hosts running and they start assigning MAC addresses to VMs.
No problem. And then all of a sudden you have another hyper-v environment, for example, maybe.
And all of a sudden you start getting duplicate MACs because these guys aren't communicating with each other.
And then you have to go in there and do some manual editing and say, this one can use MACs between here and here.
And you can allow other ones at a different range.
vCenter is going to manage that and make sure you don't have duplicates and make sure that they're unique within your virtual environment.
If you have a standalone ESXi host, then the host obviously is the one that's going to manage those MAC address assignments.
You can also go in and set a range of what they can use.
I've never really seen in a VMware environment where you – because it's always using vSphere.
I've never seen where you needed to manually set a range for MAC addresses.
I have seen with other hypervisors where you had to do that, but not with a vSphere environment.
So they can be assigned by the individual host or they can be assigned and managed by vSphere.
So that way you don't have to worry about, you know, things like conflicts and things like that.
Paravirtual RDMA.
So paravirtual RDMA is like regular RDMA.
RDMA basically means that we have systems that can read the memory of another system
without having to go through the operating system, without using the CPU on that remote system.
So in order to do this, you need physical adapters that support RDMA.
Well, if you want virtual machines that can do the same kind of RDMA access,
then you need to have a paravirtual RDMA network adapter in that virtual machine.
So what you will do when you're building your virtual machine
or if you're adding a new adapter to a virtual machine,
rather than using the normal one most of the time you'll use as a VMXnet 3 or E1000,
you'll actually use the PVRMA, RDMA network adapter.
So this will allow this paravirtual RDMA access between virtual machines.
All right.
So this is going to be more commonly used environments where you need very fast communication
between virtual machines.
And this is going to be done, like, for example, if you have any kind of, like,
high-performance compute environments or if you're doing machine learning, AI type of things
where very fast communication is important between machines in a cluster,
then you might want to enable this.
It was introduced with ESX 6.5, so you need ESX 6.5 or later, vCenter 6.5 or later.
You need to be using a distributed virtual switch, right?
You need version hardware 13 or later because that's what's going to support the
paravirtual RDMA adapter, obviously, or something obviously,
but you'll also have a Linux operating system.
And there's this thing here that the paravirtual RDMA is automatically enabled in vSphere 7.
You don't have to go into enable like you would in 6 and 6.5.
So here, if we want to enable a paravirtual RDMA on a virtual machine,
so basically what we're going to do is we're going to go to the VM.
It's going to be powered off.
We can go to edit the settings of the virtual machine.
We can select the virtual hardware we want to go in there and configure and add.
We're going to add a device.
We're going to go in and we go to add.
We're going to say add a network card.
We're going to expand that network card because normally what you'll see is just
be able to choose the port group you want to assign to it.
If you expand it, you'll also be able to go in there and change the type of adapter
it's going to be virtualizing.
And by default, normally it goes to the VMXSAT3.
You'll just change that to the PVRDMA adapter.
And then you can go ahead and say next and install that virtual adapter on there.
So it's pretty easy.
So if I can install any other NIC, but you just need to make sure that you choose a
pair of virtual RDMA adapter instead of the default VMXSAT3 or you might sometimes use
the E1000 in your environment depending upon if you have VMware tools installed or not.
VMXSAT3 does require VMware tools, but so will the pair of virtual adapter.
So vSphere 6 – I'm sorry, vSphere 6 – and vSphere IPv6.
So IPv6 is – one of those things that's been – people have been saying for 25 years
that it's like, oh, everyone, we're going to have to use it here soon, and for 25 years
we haven't had to go from version 4 to version 6 yet.
But you are starting to see more companies making a push to do that.
Not that it's this imminent disaster around the corner.
I think more people are starting to see like, okay, there's not only are we running out
of IPv4 addresses like we've been saying for 25 years, but also there's benefits to IPv6
and so people are starting to consider going there.
It's easier address space.
I don't have to worry about overlapping with, you know, things out in the public area, the
internet.
Multicasting isn't something that's used a ton.
There's certain use cases where multicasting is important, but it's starting to be used
more and more for certain services, and IPv6 is built to make multicasting really efficient,
really fast.
And routing is a real simple operation with IPv6, a little easier than with IPv4.
So if you want to enable IPv6 in your host, you can go to your DCUI, you're going to log
into there, you're going to go and configure your management network, and you'll just go
in and configure and add the IPv6.
And then, of course, you'll have to say do you want to use DHCP or static assignment
address.
But you can just do it through basically through the console.
You can go in there and enable IPv6.
Once you've enabled IPv6, you might want to also then go in and disable IPv4.
So it just depends if you want to run a dual stack or if you want to run a single IPv6-only
stack.
That's going to be up to you.
All right.
But you can also, in through the DCUI, go in there and you can disable IPv4.
So enabling IPv6 on the host and in vCenter.
So going into the DCUI, as we just discussed, you know, on our host, we can enable it.
You might also want to enable it in vCenter.
There might be some gotchas when you enable it on a host that's been running for a while.
So you might want to be kind of aware that there might be some things you'll need to
do.
So you probably want to – well, if you're rebooting the host and going to the DCUI,
you have to put it in maintenance mode and evacuate all the VMs off.
But before you take it out of maintenance mode and bring it back online, start putting
VMs back, you'll probably want to do some testing and make sure that everything's working
the way you're expecting it to work.
Okay?
So, for example, if you're using IPsec on your ESXi host and you enable IPv6, you might
find that there's some communication problems afterwards.
You can probably fix it pretty easily just by going in there and removing IPsec and then
re-enabling IPsec with IPv6 enabled, and that will probably clear up your problem for you.
Change IP address for the VCSA deployment with a static IP.
So you're going to need to update your DNS records, wait for any kind of caching to clear
out and some things like that, right?
So that's something you need to be aware of.
When you change any IP address, this can happen.
It's not just a unique thing to go into IPv6.
Any time you change vCenter's IP address, there might be some gotchas and some delays
and other devices realizing that's changed.
Delay when removing an NSX-distributed virtual port group, which is located, attached, or
deleted.
Okay?
So what they're saying here is that if you're running IPv6 and you want to remove a port
group from a distributed virtual switch, you might see it take a while and really you have
one real option.
You need to be patient and wait for it to happen.
It takes longer now.
They did say you can reconfigure and lighten the load, but that's not really changing because
now you're just not deleting the port group.
You're reconfiguring the port group.
You're shrinking the port group.
If you want to actually delete it, it's just going to take a while.
You need to be patient and wait for it to run.