[afripv6-discuss] IPv6 rollout...

Graham Beneke graham at neology.co.za
Fri Aug 3 12:59:37 SAST 2012

There is an article about this on one of our local news sites:


Also includes some interesting statistics from:



On 03/08/2012 11:18, maina.noah at ipv6.or.tz wrote:
>> According to google's
>> http://www.google.com/ipv6/statistics.html#tab=per-country-ipv6-adoption
>> ZA's v6 adouption has jumped since last week from 0.04 to 0.18%
>> Allowing ZA to steal frist place from ZM  (currently at 1.3 %) and leaving
>> TZ with the bronze with a percentage of 1.1% (I clearly have the Olympic
>> bug these days)
> Hisham,
> This is definitely some good progress for the continent and like we are
> saying in .tz, lets walt the talk. I think operators are just being lazy
> otherwise the stats above would be quite significant across the continent.
> Folks are just seating on their v6 allocation ...they have it and not
> doing anything but lets continue to sensitize everyone out there and those
> who need our support, we are here to help.
>> Hisham
> ./noah
>> On Jul 31, 2012, at 11:55 PM, Andrew Alston wrote:
>>> Hi Guys,
>>> Ok a bit more info now that I have time to sit down and write, sorry
>>> things have been rather hectic.
>>> Here is how this came about, and a bit more of the full story.
>>> The university in question was running a network without a real
>>> topology, in essence, it was a flat network, v4 only, and a massive one
>>> at that.  This was causing REAL issues, and it was the result of years
>>> and years of legacy.    The decision was taken that IPv6 would be
>>> required, but, simply put, we had to fix the network first.  So first
>>> step, how do you migrate from a flat network running a single /16 flat,
>>> to a segmented network, and do it on a live campus environment that has
>>> 38 thousand users on it every day using the network?  The answer... very
>>> very carefully, with a lot of planning, and some very careful segment
>>> and IP planning.
>>> So, the following decisions were made:
>>> A.) We get rid of NAT in entirety - if we were going to do this, we
>>> would do it properly, and the dual stack would be on live IPs in
>>> identical topology v4 and v6 network wide.
>>> B.) We divide the network into a three tier network, core, distribution
>>> and edge.
>>> C.) Core/Distribution would be routed, would have to be scalable, and
>>> we'd use SP style protocols to do this.
>>> D.) Edge would remain layer 2, but we would choose not to span any L2
>>> across distributions.  Since Core/Distribution in future will be MPLS
>>> enabled, if we need L2 between to points, we can EoMPLS it.
>>> So we did our planning, and discovered (to our horror), that changing
>>> the topology, eliminating NAT, and rolling out the wireless
>>> infrastructure we had planned, we'd need a LOT more IPv4 space.  So, we
>>> applied and were granted a second /15 PI space from AfriNIC.   We then
>>> started implementation.
>>> First step:  Pick a network segment - we chose the student residences
>>> (not because we hate the students, but because we wouldn't break any
>>> critical research if it all went horribly wrong).  Then, we moved all
>>> the student residences between a single distribution, our residence
>>> distribution.  At this point, Vlan 1 was still spanned to the residence
>>> distribution, so NOTHING had broken in doing this, all was working.
>>> Then, we created a point to point link between that distribution and the
>>> core.  On the point to point, we put a /30 v4 and a /126 v6.  (Sadly,
>>> the gear we are using doesn't support either /31 or /127).
>>> Then, we enabled ospf for v4 and ospf3 for v6 across the point to point.
>>>  There is a slight difference in the topologies at this point because
>>> the ospf for v4 was configured to ONLY carry the point to point and the
>>> loopbacks from the distributions, the rest is covered by iBGP, where as
>>> in v6, the hardware didn't do ipv6 bgp, so we had to do full route
>>> distribution of v6 in OSPF3.
>>> Note at this point, we had still had zero downtime.
>>> Then, for each residence between the distribution, we created a vlan,
>>> and assigned it an IP segment and an IPv6 segment.  To avoid mass routes
>>> in our routing tables, these segments were all taken out of supernets we
>>> had dedicated to each distribution, and the supernets were what we
>>> pushed into the routing table on both v4 and v6 level.  So, the vlans
>>> were now created on the distribution, the routing was working.  Fixed up
>>> the DHCP for v4 as well, so that was in place and ready to go with the
>>> correct scopes.  (Note, we are using RA for v6 at this point, we haven't
>>> gotten around to DHCPv6 yet, so most people are still hitting the DNS
>>> servers on v4 addresses, since we can't push DNS via RA).
>>> Note: Still ZERO downtime to anyone
>>> Then, we took the created vlan's on the distribution, trunked them down
>>> to the edge switches, waited till after hours, and moved the edge ports
>>> into the correct vlan's.  (Different vlans for student pcs and wireless
>>> aps etc).  The actual move into the correct vlans was like, a single
>>> command on each switch.  Then simple forced a port flap one very port as
>>> we went.  The port flap was to force a DHCP reallocation on v4.
>>> Bang, the residences came up on the new topology with v4 and v6 - total
>>> downtime to the clients - less than 30 seconds.
>>> Then, we did a rinse and repeat job through the various distributions
>>> (we're still busy doing some of them, 6 outta 11 done so far, and
>>> probably around 300 or 400 edge switches tagged correctly).
>>> Once we were sure the topology was working, and the IPv6 was working,
>>> next step was to enable the ipv6 on the proxy servers, so that they
>>> could fetch via IPv6.  We did this, and instantly saw around 30% of the
>>> traffic coming in via v6, primarily google, youtube, facebook and
>>> akamai.  Note however, at this point the clients were still seeing the
>>> proxies via v4, though the proxies were fetching via v6.  So next step,
>>> put in quad-a records for the proxy servers and for the pac file round
>>> robin.  Suddenly, everyone who had a v6 address was fetching from the
>>> proxy servers via v6, irrespective of if the proxies were fetching v4 or
>>> v6.
>>> Suddenly, we had a situation where 50% of the traffic coming in was via
>>> IPv6, and we infact peaked at well over 100mbit of IPv6 traffic today
>>> coming in off the Internet.
>>> Our next steps of course are to migrate the rest of the distributions
>>> and edge to the new network, and infact in the next 10 minutes we'll be
>>> moving another thousand edge ports into this.  Once this is done, we'll
>>> start looking closely at the server infrastructure and how we go about
>>> putting the rest of the production servers both into the new topology
>>> and IPv6 enabling them.  We expect this to be the most problematic part,
>>> since we know there are certain services which have issues with IPv6,
>>> but we'll work around those when we get there.
>>> In summary - it is entirely possible to take a network with around 15
>>> thousand wired network points, a few hundred wireless access points, a
>>> few thousand VOIP phones and completely redeploy it both on a v4 and a
>>> v6 level with almost no downtime if the planning is correct.  The
>>> traffic levels also prove, there is IPv6 content out there, lots of it,
>>> and we're happy to use it!  It just takes some planning, some
>>> forethought and some people willing to work really hard at strange hours
>>> getting it done.
>>> For interests sake, graphs can be seen here:
>>> http://graphs.tenet.ac.za/iris/browser/browse?username=UFS&selectedmnemonicgroup=TSN81
>>> The graph marked vl1081 is the IPv4 interface to TENET (The South
>>> African NREN), the graph marked vl3081 is the IPv4 interface to TENET.
>>> We specifically asked them to provide v4 and v6 on separate interfaces
>>> as it did allow for us to see the traffic on a more individual basis as
>>> well, which was useful.
>>> Hope this answers some of the questions I have been sent off list and
>>> provides hope for those who believe that IPv6 migration is impossible -
>>> never forget - we did it on both v4 and v6 *at the same time*, on a live
>>> network, with no downtime, so if anyone doubts it can be done, we're
>>> proof that it can.
>>> Thanks
>>> Andrew Alston
>>> Network Consultant
>>> NOTE: I write the above as a private individual and private consultant
>>> and have gained specific permission from my client (The University of
>>> the Free State) to relay this story.  I would like to say a special
>>> thank you to them for allowing me to share this with you as well.
>>> On 31 Jul 2012, at 3:58 PM, Maye diop <mayediop at gmail.com> wrote:
>>>> Dear Andrew,
>>>> Congratulations.
>>>> I look forward more details to share with my universities.
>>>> Best Regards.
>>>> Le 31 juil. 2012 07:11, "Andrew Alston" <alston.networks at gmail.com> a
>>>> écrit :
>>>>> Hi Guys,
>>>>> So, while i'll be sending out a lot more data soon, with a lot more
>>>> information on exactly what we did and how we did it etc, I thought
>>>> I would share some news that I for one found rather exciting.
>>>>> Yesterday evening starting at around 7pm one of the South African
>>>> universities turned up IPv6, in a fairly consistent manner.  Now, I'm
>>>> not talking about turning up IPv6 on a few servers, I'm talking about
>>>> integrating it into every part of their network.  By 2:30am this
>>>> morning it was running on all their proxy servers, all their
>>>> residence networks, the wireless networks, all the lab PC's and a
>>>> good portion of the staff network.  The topology used was identical
>>>> to that of the IPv4, and as the rest of the network is migrated to
>>>> the new IPv4 topology V6 will be implemented on everything in dual
>>>> stack along side that as well.
>>>>> Now, here is where things get interesting, another network dual
>>>> stacked is no real news, so lets talk about traffic levels.
>>>>> The University in question is now running anywhere between 30 to 50
>>>> percent of its internet traffic on IPv6, and its working flawlessly
>>>> so far.  So flawlessly infact that even with Apple's default
>>>> implementation of Happy Eyeballs that tests RTT and defaults to v4 if
>>>> the v6 latency is higher, the apples we tested on running lion and
>>>> mountain lion were still choosing ipv6 most of the time.
>>>>> I am not going to say this little rollout has been easy though, we
>>>> had to rearchitecture the entire network (that had to happen anyway
>>>> for various reasons), and we added the v6 as part of that project.
>>>> It would not have been possible to do that without first getting our
>>>> hands on another /15 worth of IPv4 space though to allow that
>>>> rearchitecturing to happen properly.
>>>>> As I said though, in coming days we'll write up what we did with a
>>>> lot more detail and send through some graphs and other information, I
>>>> just had to share the fact that we're seeing at points half the
>>>> traffic on a standard university coming in from the internet over
>>>> ipv6!
>>>>> Thanks
>>>>> Andrew Alston
>>>>> Network Consultant_______________________________________________
>>>>> afripv6-discuss mailing list
>>>>> afripv6-discuss at afrinic.net
>>>>> https://lists.afrinic.net/mailman/listinfo.cgi/afripv6-discuss
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Graham Beneke
Network Engineer      | Neology (PTY) Ltd.
graham at neology.co.za  | http://www.neology.co.za/
Dir: +27-10-500-5906  | Suite 301, Block C, Eva Park
Tel: +27-11-476-1933  | Cresta, Johannesburg
Skype: grbeneke       | Jabber: graham at neology.co.za

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