Hey, welcome back.
In the previous video, we identified
that on a Cisco router, we can create
logical separate routing tables which
are VRFs, virtual routing and forwarding instances,
and then we can assign interfaces to that VRF.
And when we do, we get a new directly connected route inside
of that VRF.
Now what I like to do in this video
is talk with you about two different options.
Not my fault, don't shoot the messenger.
But two different options for creating a VRF
on a Cisco router.
And also the syntax to take an interface WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And also the syntax to take an interface
and say, you belong to this VRF.
And with fear of light, because we
don't have to worry about layer 3 VPNs or MPLs,
it's really just basically a 2-step process.
We want to create the VRF.
And then after we create the VRF,
we'd want to assign at least one interface to that VRF
so it has at least one route in that virtual routing
and forwarding instance.
Now the creation, there's two different ways
of creating a VRF.
And one of those ways is for IPv4 only, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and the other way is if you're doing IPv4 and/or IPv6.
So I wanted to point out both ways of doing it
so that if you see the configuration,
you won't freak out and say, what,
I didn't learn it that way.
Well, actually both ways of creating it.
So the creation for a VRF, a virtual routing and forwarding
instance, if we're the IPv4 only flavor,
the syntax is IP, space, VRF, space.
And then you need to give it a name.
And press Enter and-- bada-bing, bada-boom-- you
have a new virtual routing and forwarding instance
called whatever that name is.
Let's call it CUST1. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Let's call it CUST1.
So I'm just going to give it the name of customer 1.
And that will support just IP version 4.
If we want to do a VRF that will support IPv4 and/or IPv6,
the syntax is this, VRF, space, definition, space.
And then we go ahead and give it a name.
So that creates a VRF called Customer 2.
And then we take one more step, we'd
be placed in VRF configuration mode.
And from here, we'd specify address family, space, and then
we specify either IPv4 or IPv6.
So address family, the keyword simply says, Oh, what's WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So address family, the keyword simply says, Oh, what's
the protocol stack we're working with?
If we're working with IPv4, we'd add that, if it's IPv6
we'd specify IPv6.
So either way would create the VRF.
And then the second step is once these VRF's are created,
we then go to the interfaces.
And then interface config for these interfaces,
we'd use the command, VRF forwarding and then the name.
So if we wanted this gig 0/0 to be associated with VRF Customer
1, we'd say, VRF forwarding Customer
1, the name of our VRF.
Or if we want this interface gig 0/3 WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Or if we want this interface gig 0/3
to be associated with the VRF called Customer 2,
we'd say VRF forwarding, and then that name
that we assigned to that VRF, which is Customer 2.
And one thing that surprised me when I was initially
learning VRFs is that when you apply or associate
an interface with a VRF, whatever IP address was
on that interface, that IP address and that network that
directly connected the network, that
was associated with the global routing table.
So when you assign an interface to a VRF,
it, bam, just warps it and removes the IP address.
So if you want to use the same address, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So if you want to use the same address,
you can but you have to reapply it
once you specify the interfaces part of the VRF
called Customer 1 or Customer 2.
So that's the basic 2-step process
for getting VRFs working.
Create the VRF and assign the layer 3 interfaces to it.
And check this out, it doesn't apply just to physical routers.
What if we've got a multilayer switch with Switch Virtual
Interfaces, layer 3 virtual interfaces for each
of the VLANs?
It'd be the same process.
We create the VRF and assign those SVIs,
those layer 3 interfaces to the VRFs
where we want them to belong. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
where we want them to belong.
So in the next video, let's do this.
Let me walk you through what that
would look like conceptually so we
can apply our concepts of VRF lite
to either a physical router or a multilayer switch who's
also performing routing.
So we'll jump into that in the very next video.
So I'll see you there in just a moment.
Meanwhile, I hope this has been informative for you.
And I'd like to thank you for viewing.