Dual-stack switch configuration covers enabling both IPv4 and IPv6 on a Cisco switch management interface using VLAN 1 as the target. The process includes activating IPv6 support via SDM templates, assigning a link-local address, and configuring a static global unicast address.
Dual Stack Switch Config
We're going to configure this switch to be dual stack. Dual stack means that it has both IPv6 and IPv4 addresses on it.
In this case right here it is a switch port, so we're not going to configure all of our ports to be IPv6 routed ports. They're all switch ports. But what we can configure is the management interface, which at this point in time is VLAN 1.
Let's take a look at that first. I'm going to type in show run, and we're going to take a look at interface VLAN 1, because that's where the management interface is at, and we see that there is an IP address associated with it. So what I want to do is associate an IPv6 address to it.
The first thing that I need to do is activate IP version 6 addressing on this device. I'm going to do that in the global configuration mode, and I'm going to type in sdm prefer, and it's going to be ip version 4 — excuse me, it's going to be dual-ipv4-and-ipv6, so it's quite crazy there — and we're going to set that as being the default operation. We hit enter and now it's going to configure it.
I've actually already done this on the switch, otherwise it would pop up with some notification letting us know that it is now configured. Once we've done that, we would need to do a reload on this server, so I type in reload to do a reload on the server. As I mentioned before, I've already gone through this process, so we don't need to do that at this point in time.
Next, what I'm going to do is get into the interface to configure it. I'm going to get into the global configuration mode, get into interface VLAN 1, and now I'm in the interface and I can assign an IP version 6 address just like the routed interface.
There are some commands that it can do with this, like ip version 6 enable, in which case it would just create a local link address on this device so then it can communicate on the local network. In fact, let's go ahead and do that. Let's go ahead and type in enable for that to pop up there, and then I'm going to do show ip version 6 interface brief, and we can see that it has created a local link address on VLAN 1. So now it can communicate. Remember, it has to have that local link for IPv6 to operate, so even if we were to just create a regular IPv6 unicast address on this device, which we're going to do in a second, that would show up in that network right there.
Next, what we're going to do is configure an address on here. What we want is somewhere within our range, which is fc00:1::, and 12 is the one I'm going to assign to the switch. And then we're going to put the slash prefix length, which is 64. If I wanted to do an EUI-64 address, then I would just leave the 12 off of here and then type in EUI-64 at the end of this. But I don't want to do an EUI-64, so I am going to want to just assign it to 12, and I hit enter on that.
Then I'm going to do show ip version 6 interface brief, hit enter, and now we see both of those are now assigned to this device. If I wanted to try to communicate out, I could ping fc00 colon colon colon one colon colon three. It should be a pingable address. I am not in the — I'm in one of the submenus, so I have to type do at the beginning of that — and successful.
So now we have configured this interface with an IPv6 address on it, and this is mainly, at this point in time, just as a management interface, so I'd be able to get to this device using IPv6.
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