Wednesday, May 3, 2017

Moving to IPv6 in the Lab

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IPv6 is one of those technologies that I've been wanting to dig into further.  I know enough that I can get through the certification exam of the day with a little book time to refresh, but I don't know it well enough.  It's not something I've been avoiding, just something that I've kept putting off because something was more pressing, more interesting, or potentially more useful.  So there's no time like the present. Let's get started.

I began by reconfiguring the network to better align with all the blog posts and docs that I've read to date.  I originally had the 3750 doing the intraVLAN routing, but I decided to simplify and push everything out to the 2821 at the edge for now.  So the 2821 and 3750 are doing router on a stick.  There are 2 VLANs I'll be using (10 and 20 for now, additional VLANs are there but not IPv6 enabled yet), so the /60 Comcast is currently handing out that can be broken down into 16 /64's will suffice.  I think a lot of areas are getting more than a /60, but it's more than enough for now.

On the 2821, we'll start by enabling ipv6 routing.  Naturally, the commands are a bit different here and there.

ipv6 unicast-routing
ipv6 cef

Then on the outside interface, we'll pull our /60.  If your ISP is handing out bigger chunks, adjust your hint accordingly.

interface GigabitEthernet0/1
 ipv6 enable
 ipv6 address autoconfig default
 ipv6 dhcp client pd hint ::/60
 ipv6 dhcp client pd COMCAST

First we enable ipv6 on the interface and then pull a /60 and put it into a pool called COMCAST.  In a lot of other docs online, I see the addition of "ipv6 address dhcp" added on the outside interface as well.  But my router/IOS combination wouldn't take that command and it's working fine without it, so keep this in the back of your mind.

Next, we'll go onto the inside interfaces.  We'll set up the IPv6 addresses and have a little ROAS review here too.

interface GigabitEthernet0/0
 no ip address
interface GigabitEthernet0/0.10
 encapsulation dot1Q 10
 ipv6 address COMCAST ::1/64
 ipv6 dhcp server COMCASTPOOL
interface GigabitEthernet0/0.20
 encapsulation dot1Q 20
 ipv6 address COMCAST ::2:0:0:0:1/64
 ipv6 dhcp server COMCASTPOOL

What we've done here is put the first /64 from the COMCAST pool onto VLAN 10, and the second /64 onto VLAN 20.  The next line on the interface sets up the dhcp options for the two VLANS.  The only options that I've currently configured are the DNS servers.  I'm actually using my own Domain Controllers (which is what you should use if you have them), but for here I'll put in Google's.  There's some timers that may need tweaked in regards to neighbor discovery, but that's a little beyond my understanding at this point.  I'll get into that at a later date.

ipv6 dhcp pool COMCASTPOOL
 dns-server 2001:4860:4860::8888
 dns-server 2001:4860:4860::8844

So now we have full IPv6 connectivity on just about everything in the lab (for some reason, none of my Virtualbox guests can ping past their own Ethernet NIC, but that's a topic for another day).  I've disabled IPv4 completely on a test machine (Server 2008 Enterprise) and loaded up Yahoo.

So far so good.  We've got connectivity.  The NIC settings are shown to demonstrate that IPv4 is indeed disabled.

What's next?  I would like to move intraVLAN routing back down to the 3750 and have a single routed link between it and the 2821. Then I want to move the DHCPv6 functionality for each VLAN down to the domain controllers so I can manage all the IPv6 bits with Windows IPAM as I do now with the IPv4 bits.  And finally, I need to update the IOS on my 3750 to an image that supports IPv6, among other shortcomings I'm currently hampered by.

But first things first, I'm going to move my Hyper-V servers from Server 2012r2 to 2016 and finally get them into a failover cluster.  Between that and getting some shared storage together for the cluster should get me through a good section of the MCSA 2016 topics.


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