[afnog] Four Misconceptions About IPv4 to IPv6 Migration

[Andrew Alston]

Interesting article, and applicable in certain environments, but in other environments not so much.

Let me comment specifically on section (1) from the perspective of a provider.

The article is correct in the fact that a LOT of gear does support v6, most “modern” hardware has v6 capability in it.  That being said, it is not the support or lack thereof when it comes to v6 that is the problem, but rather the functionality of the v6 vs the v4 that creates issues.  Let me explain using an example.

A provider metro network, with a thousand MPLS enabled edge devices, made by a particular vendor and purchased less than a year ago.  Assurances were sort that MPLS for v6 would be coming down the line, sadly, it hasn’t arrived and it seems is no longer planned for that hardware.  So, what does this mean.  I can still do MPLS over v4, meaning I use functionality which is CRITICAL, and I can run v6 over the top of the v4 EoMPLS circuits created, and over to the top of v4 based VPLS networks etc.  However, I *CANNOT* create my MPLS networks on V6.  Meaning that I am stuck using v4 loopbacks and v4 point to points (or at absolute minimum, v4 loopbacks and CLNS routing on the point to points using ISIS).

This means that I cannot “migrate” to v6, I can add V6 on top of the v4, but I cannot get rid of the v4 and still require it for every device I put out there.  However, if functionality such as LDP6, the ability to do martini and kompella over v6 and other such things existed, for that particular network I would have NO need for v4.  Effectively this would free up 5000 v4 addresses.  But, even with LDP6 now out there (or segment routing which is another option) a.) it will not be supported on the hardware I’m running b.) even on the hardware ths DOES currently support LDP6, the functionality USING LDP6 is *FAR* from having parity with v4.

V6 is coming, there is no doubt about it.  If we don’t deploy it, we’re gonna be in trouble.  NAT is not a sustainable solution, never has been, never will be, and the world is running out of v4.  But until there is what I refer to as protocol parity, the deployment will be hampered, and that protocol parity is still (sadly) very very far away.  Right now, no matter how much you want to, you still have to build your v6 in a provider environment ON TOP of your v4, and you have to be VERY careful with your hardware purchasing decisions if you wish to avoid a situation where you will be stuck in this scenario for the long haul.

(Please don’t mistake what I am saying by the way, such things should not stop the deployment of V6 totally, and if you have to build v6 on top of v4 right now, its in your interests to do so, and that is what my employer has done, I am merely stating that it would make the case so much stronger if the protocols actually had parity in the functionality)

Andrew


From: afnog [mailto:afnog-bounces at afnog.org] On Behalf Of Nabil Badri
Sent: 04 September 2015 13:14
To: afnog at afnog.org
Subject: [afnog] Four Misconceptions About IPv4 to IPv6 Migration

focusing on the net i find this article talks about the Four Misconceptions About IPv4 to IPv6 Migration.I just want to share to you this article.this  is the link,and waiting your comments .
http://www.6connect.com/blog/misconceptions-ipv4-to-ipv6-migration/
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