Category: IPv6

Once you’ve spent a few hours trying to understand the implications of IPv6, you quickly realize that the only significant change is the increase in the address length. All the other goals that some people had been talking about were either forgotten or failed due to huge mismatch between idealistic view of the Internet IPv6 developers had 15 years ago and today’s reality. However, you still find mythical properties of IPv6 propagated across the Internet. Here are a few I’ve found; add your favorites in the comments.

IPv6 provides service/location separation. Total nonsense. The only mechanism used to find services is still DNS and it’s still used from the wrong position in the protocol stack.

Shivlu left an interesting comment to my IPv6 is not ready for residential deployment post. He wrote: “Still no customer is ready for IPv6. How do I convince them?” The unfortunate answer to this problem is: you can't, but they'll only hurt themselves. If they persist long enough, they’ll become obsolete.

The migration issues are just one of the topics covered in the Enterprise IPv6 Deployment workshop. You can attend an online version of the workshop or we can organize a dedicated event for your team.

The web content providers have long realized that their customers have too many choices. Zvezdan Martič, one of the participants in the last year’s Slovenian IPv6 summit roundtable succinctly explained this phenomenon: “nobody cares whether my web site can be viewed in Internet Explorer or Firefox; if I don’t support the major browsers, the customers will find one of my competitors that does.”

It’s almost unbelievable: more than 10 years after the IPv6 specs have been completed, someone finally realized it would be a good idea to specify the minimum requirements for a decent IPv6 CPE router. While this document will not solve the lack of low-cost IPv6-ready CPE devices, it’s definitely a step in the right direction, more so as it clearly acknowledges the need for DHCPv6 (some people still believe SLAAC is the solution to every problem ever invented).

Here are a few highlights from the document:

When the current variant of IPv6 was selected 15 years ago, seamless integration with IPv4 was a big deal, resulting in NAT-PT architecture. NAT-PT tried to solve too many problems and (as I pointed out in my IPv6 Deployment workshop), while the 6to4 NAT is manageable, the 4to6 NAT is horrific (NAT64 and DNS64 are more reasonable; more about them in an upcoming post).

NAT between IPv4 and IPv6 hosts is just one of the topics covered in the Enterprise IPv6 Deployment workshop. You can attend an online version of the workshop or we can organize a dedicated event for your team.

To make matters worse, the NAT-PT implemented in Cisco IOS is totally broken due to removal of fast switching support in IOS release 12.4(20)T and numerous other releases. As I wrote a year and a half ago, removing fast switching will bite us eventually … and so it does when you try to use NAT-PT.

The main driver for IPv6 deployment is the IPv4 address space exhaustion, caused primarily by fast growth of residential users.

Each residential user needs an IP address, a small company doesn’t need anything more and even a reasonably-sized company can survive with a few IP addresses.

One would expect the vendor readiness to follow this pattern, but the situation is just the opposite: while the enterprise networking devices have pretty good IPv6 support (Data Center components from some vendors are a notable exception), the vendors serving the residential market don’t care.

The Service Provider-related IPv6 challenges are covered in my Market trends in Service Provider networks workshop. You can attend a web-based tutorial version or we can organize a dedicated workshop event for your team.

Cisco has recently published two excellent design guides: Deploying IPv6 in Campus Networks and Deploying IPv6 in Branch Networks. As expected from the engineers writing Cisco’s design documents, these guides contain tons of useful information and good recommendations; they’re a highly recommended reading if you’ve started considering IPv6 deployment in your enterprise network. These design guides are part of Design Zone for Branch and Design Zone for Campus.

IPv6 deployment issues are just one of the topics covered in the Enterprise IPv6 Deployment workshop. You can attend an online version of the workshop or we can organize a dedicated event for your team.

A while ago a senior Service Provider network designer told me that they have serious issues with IPv6 deployment as IPv6 requires a separate PPPoE session from the CPE devices which significantly increases their licensing costs. The statement really surprised me; PPP was designed to be a multi-protocol environment and it’s very easy to configure IPv4 and IPv6 over a single PPP session in Cisco IOS. I think I might have tracked down the source of this “information” to the 6deploy IPv6 and DSL presentation which states on Page 11 that “Separate PPP sessions are established between the Subscriber’s systems (or CPE) and the BBRAS for IPv6 and IPv4 traffic”.

Being too Cisco-centric, I cannot figure out whether this claim has any merit, as it clearly does not apply to Cisco IOS. Are there really boxes out there that are so stupid that they cannot run two protocols across a single PPPoE session?

One of the most common questions asked by my enterprise customers is “Who needs IPv6?” Since IPv6 does not add any significant new functionality (apart from larger address space), you can’t gain much by deploying it in an enterprise network … unless you’re huge enough that the private IPv4 address space (RFC 1918) becomes too confining for you. A good case study is Halliburton; you’ll find the details in Global IPv6 Strategies: From Business Analysis to Operational Planning book (my review).

With the recent Cisco’s push into the Data Center environment and all the (not so very unreasonable) fuss around IPv4 address depletion and imminent need for IPv6, I wanted to check whether an all-Cisco shop could do the first step: deploy IPv6 on Internet-facing production servers. If you follow the various design guidelines, your setup will have at least the following elements (and I bet someone from Cisco has already told you that you also need XML firewall, Ironport and WAAS appliance):

Now let’s see how well these boxes support IPv6.

I’m describing the Data Center IPv6 deployment issues in the Enterprise IPv6 Deployment workshop. The diagram above was taken straight from the workshop materials.

ITU (the organization formerly known as CCITT) is having a bit of a relevance problem these days: its flagship technological achievements, including X.25, ISDN, ATM, and SDH, are dead or headed toward oblivion … and a former pariah, a group of geeks, is stealing the show and rolling out the Internet. No wonder their bureaucrats are having a hard time figuring out how to justify their existence. For years they’ve been lamenting how much they’ve contributed to the Internet (highly recommended reading for Monty Python fans) and how their precious contributions were unacknowledged. Now they came forth with a “wonderful” idea: the history of IPv4 address allocation proves that the wealthy nations and early adopters managed to grab disproportionate parts of the IPv4 address space (well, that’s true), so they made it their mission to protect the poor and underdeveloped countries in the brave new IPv6 world. In short, they want to become an independent address allocation entity (RIR). It looks like another worldwide bureaucracy is precisely what we need on top of all the other problems we have with IPv6 deployment.

During the IPv6 summit in Slovenia I’ve participated in a roundtable organized by our Ministry of Higher Education, Science and Technology. One of my points was that the government should require true IPv6 support in all its IT procurement processes to promote IPv6 adoption (I have to admit I’ve borrowed a few ideas from Geoff Huston’s “Is the Transition to IPv6 a Market Failure?” article) … and one of the participants (coming from the Service Provider industry) answered that “that’s common hygiene”. I’m not so sure.

Topics like this are covered in my Enterprise IPv6 Deployment workshop. Learn more about my workshops from my web site.

One of the biggest challenges facing the Internet core today is the explosion of the IP routing and forwarding tables, which is caused primarily by traffic engineering and multihoming requirements. Things were supposed to get better when IPv6 introduced strict hierarchical addressing (similar to the phone number addressing, where the first few digits always denote the country code).

Unfortunately, the hierarchical IPv6 addressing idea relied on incredible belief that the world will shape itself according to the wills of the IETF working group members. Not surprisingly, that didn’t happen and the hierarchical IPv6 addressing idea was quietly scrapped, giving us plenty more prefixes to play with when trying to pollute the global IPv6 routing tables.

I have to admit I have no hands-on Service Provider IPv6 experience (but then there are not too many people that can claim they do) and I don’t attend RIPE meetings, so I might have a completely wrong impression, but here it is: Is it just my perception or do we really lack any production-grade means of end-user multihoming in IPv6?

The high-end books published by Cisco Press are usually pretty good, but every now and then they manage to produce a masterpiece that has all the potential to become a legend. The “IPv6 Security” book by Scott Hogg and Eric Vyncke is definitely in this category and is a must-read for anyone who plans to deploy IPv6 in the future (that should include around 100% of the network engineers).