Categories R&S

IPv6 – The beginning – Addressing plans and adresses configuration

I’m starting to work on IPv6.

In order to get a good understanding of it, I will make a couple of posts and then I will get back to it later.

 

I have already read a lot, watch videos a lot about IPv6, take some exams about it but I still have some issue to really get it.

 

I guess that’s because I haven’t practice it for real.

Still I can troubleshoot it, make basic configurations but I don’t really get IPv6…

 

I’m not going to talk about all the address theory, the end of IPv4 and all those stuff. You can read about this on multiple websites.

 

I will try to setup a network and see how it gets.

Here is the network I’m going to configure.

IPv6 - basic

And here is the first problem.

What IPv6 addresses am I going to use ???

 

I search on the internet and found some good advices.

There is one good guide here: http://www.ipv6forum.com/dl/presentations/IPv6-addressing-plan-howto.pdf

One good post here: http://www.insinuator.net/2014/05/ipv6-address-plan-considerations-part-3-the-plan/

And of course from Cisco: http://www.cisco.com/c/dam/en/us/td/docs/solutions/CVD/Aug2013/CVD-IPv6AddressingWhitePaper-AUG13.pdf

 

Well that should be enough info to find an IPv6 address plan for a lab…

 

So we need addresses for the interco between the routers.

Addresses for the interco between the routers and switches.

Some more addresses for the vlans and end hosts.

And finally some for the loopbacks.

 

 

I picked up a /32 for the complete address scheme: 2001:0db8:: /32

By the way this 2001:0db8:: is for documentation purpose as per RFC 3849 so this should be good for lab.

 

2001:0db8:1:: /48 will be for global infrastructure and I will break it down in /126 for point-to-point link.

 

Then we have three locations, I will use:

2001:0db8:10:: /48 for site 1.

2001:0db8:20:: /48 for site 2.

2001:0db8:30:: /48 for site 3.

 

Now let’s break this down for site 1:

2001:0db8:10:1:: /64  is reserved.

 

2001:0db8:10:2:: /64  is for site 1 infrastructure. I will use /124 for point-to-point link.

 

2001:0db8:10:10:: /64 is for vlan 10.

2001:0db8:10:11:: /64 is for vlan 11.

2001:0db8:10:12:: /64 is for vlan 12.

 

I use the same principle for site 2 and 3.

 

And last is our loopbacks…

Well it seems I should use /128 for loopbacks so let’s try that 2001:0db8:99:: /128

 

Here is the network diagram with the addressing.

IPv6 - addressing

 

I’m going now to configure that.

Starting with R3.

 

First, turn on ipv6 as it’s not on by default.

R3(config)#ipv6 unicast-routing

 

Now time to configure the IPv6 addresses on the interfaces.

R3(config)#int eth 0/0
R3(config-if)#ipv6 address 2001:0db8:1::15/126

R3(config-if)#int eth 0/1
R3(config-if)#ipv6 add 2001:0db8:1::6/126

R3(config-if)#int eth 0/2
R3(config-if)#ipv6 add 2001:0db8:1::9/126

R3(config-if)#int eth 1/0
R3(config-if)#ipv6 add 2001:0db8:1::d/126

 

Let’s do the same on the other routers.

Nice one, from R3 I can ping the other routers.

R3# ping ipv6 2001:DB8:1::a
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1::A, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/8/25 ms
R3# ping ipv6 2001:DB8:1::f
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1::F, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/9/28 ms
R3# ping ipv6 2001:DB8:1::5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1::5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 5/7/14 ms
R3# ping ipv6 2001:DB8:1::16
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1::16, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/11 ms

 

However, as expected, R1 can’t reach R5.

R1#ping ipv6 2001:0db8:1::f
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1::F, timeout is 2 seconds:

% No valid route for destination
Success rate is 0 percent (0/1)

 

We will fix that later on.

 

I will finish the addresses configuration on all devices and then we will see how end host get an IPv6 address in the next post.

 

Thank you for reading.

 

 

 

 

IPv6 – The beginning – Addressing plans and adresses configuration