Monthly Archives: March 2014

Will IPv6 actually ever take off? – Article #1

I am going to write a series of articles on IPv6 in the coming months. The first will be to look at the adoption rates for IPv6 and ask the question – “is IPv6 actually ever going to take off?”

Following on from this post I will post some articles on timing and triggers and then some practical advice on how you would go about actually deploying IPv6 in your environment.

So, – who has adopted IPv6?

Not many people according to google, well the % of people actually using IPv6 to transfer data across the internet right now is 2.75% of total traffic load. But usage is growing faster now than ever before. 2013 saw an increase 1.5 times of the previous 5 years.

Google V6 Usage Stats






It  also matters what country you live in as well. The USA has a healthy take up rate and is leading the way, also use in France and Germany is growing fast.







Cisco has a different view – if you hop on their V6 stats site @ you will see much different numbers being shown for rather different views. One in particular that is quite interesting is IPv6 prefixes being advertised.

This shows a similar pattern to usage in that North America and North Europe are leading the way, but a much heavier increase in % of prefixes comparing V6 to V4 route tables.V6prefixes






This tells us that although we might not be using V6 for transport today, it’s there ready and waiting advertising V6 networks in readiness for when we decide to make the switch.

So, the ISPs, North American and European countries are starting to enable their enterprise edge and ISP transit networks – so what about the rest of us? For the most part larger enterprises are looking at the business case, and deciding to sit on it for now. If anything the predominant action seems to be to apply for an IPv6 prefix, and maybe run a small IPv6 POC or Pilot.

Of course this would all change in flash if next time you called your ISP to move your home DSL or relocate your data centre internet carriage your ISP turned around and dished out V6 addressing instead of IPv4 as their allocation had been depleted  – but we are still a long way from that scenario yet. There is no question that the IPv4 address space is running out or has run out in some regions, but the local registries in region are still happily dishing out IPv4 space.

We can see from the graphic below, the IPv4 depletion rates brakes came on hard in late 2011, but this hasn’t stopped the strong downward trend. My best guess would be that you won’t get more than 3-4 years before the scenario above becomes a reality in some if not all of the regions.

IPv4 Depletion








So, to the original question “is IPv6 actually ever going to take off?” ….the answer is “yes, it will”. There are very few alternative high quality technology solutions that have as much existing investment & proven ability that can scale to address the explosion of internet enabled devices that will proliferate in the next decade.

However to reach critical mass to get a wholesale swing to an IPv6 first approach a much heavier v6 take up needs to occur globally and for that there needs to be a compelling reason or trigger event for businesses to consider a proactive investment in IPv6. I will discuss some of these in my next post.





Nexus 3000 Family – is it great low cost core switch?

I have generally shied away from recommending that businesses deploy a Nexus 3000 core in their data centres, one of the reasons has been around platform / feature support and the other around NX-OS release trains; for example-

The Nexus 3K is designed for low latency trading environments so that Cisco can compete with Arista and as such low latency is king. This means the advanced features (and maybe silicon, depending on the model) you get will not be as advanced as the traditional enterprise platforms i.e. N5K, N7K etc. Also features such as FCoE, OTV etc have never been road mapped for the N3K. Not surprisingly then the N3K also follows its own release train for NX-OS updates and patches.

That was enough to convince me that this switch should do what its good it and mainly be left in the environment is was designed for. Each time a customer asked me should they deploy this as a core switch my first reaction was “err, probably not”…until recently.

In this particular environment the requirements were fairly straightforward (they mostly are anyway) and could be summed up as;

  • We need 1 & 10G L2 switching on 96 ports at the core
  • We need an IGP and static routing, and a little policy overlaid on that IGP
  • We need high availability across the core, with load sharing & fault tolerance
  • We want to continue to use our existing management tools to manage the environment

In comes the N3K. Now the small set of requirements above are fairly generic, but could be a typical of a 1000 medium size businesses out there today. Given those requirements the final solution ended up looking like;

  • A pair of Nexus 48 port 1/10G switches in a vPC cluster
  • Peripherals connected in via vPC port channels split across boxes (FW’s, Blade, rack, Rtr’s)
  • HSRP, & EIGRP with static route redistribution and some smarts thrown in for fun
  • Standard management with SSH, NTP, SNMPv2, ACLs and role based access controls
  • Plenty of bandwidth with a 40G vPC peer-link between switches, and 20G north/south to the blade servers

In summary, if you don’t need the bells and whistles of advanced DC technology such as Unified Fabric, L2 Multi-pathing, & clever DCI stuff, and can live with a standard L2, L3 design and topology with a known (& constrained) port count capacity, then the N3K may be the switch for you.

Topology Overview