Erion Ltd - IPv6 Training

David Holder is to speak at this year’s Storage Developer Conference in Santa Clara. Erion has a long history of working to IPv6 enable networked storage solutions and in particular the Open Source Samba implementation of the CIFS/SMB protocols. This year, Dr Holder plans to give a presentation on how to IPv6 enabled storage applications. The full abstract is below.

IPv6 Enabling CIFS/SMB Applications

Today IPv6 is no longer the protocol of the future, it is being extensively deployed in production networks. The central pool of IPv4 addresses will be exhausted in 2010 to 2011. As a result, Governments and organisations world-wide have been mandating its use for a number of years. As a CIFS/SMB developer, the time has come where you can no longer ignore IPv6.

IPv6 is the default protocol in all major operating systems, including Windows Server 2008 and Windows 7. CIFS and Active Directory have had support for IPv6 for a number of years.

This paper will address the key issues facing CIFS/SMB developers when migrating their applications to IPv6. It will provide a review of the status of IPv6 in Samba and Windows and describe how CIFS/SMB applications should be migrated to IPv6. This presentation will also include a brief IPv6 API and porting tutorial presenting the key things that developers need to know about IPv6 and the IPv6 socket API in order to effectively use IPv6 in their applications.

Dr David Holder is closely involved in the migration of Samba to IPv6. He has worked with IPv6 for well over a decade and is a regular speaker at global IPv6 conferences.

Erion’s David Holder presented at the Global IPv6 Summit in Taiwan today. His talk entitled IPv6 Enabling Unix/Linux and Windows Integration provides a summary of the status of IPv6 in heterogeneous environments and included a case study on IPv6 enabling Samba the world’s leading Windows - Unix/Linux integration package.

Much progress has been made in the IPv6 enabling of Samba. However, many commercial integration products and products built on Samba technology (such as NAS boxes) remain IPv4 only.

The Global Summit included presentations from many of the leading players in IPv6 from around the world. It was particularly interesting to see the significant progress that has been made in the deployment of IPv6 in recent months.

Dr Vint Cerf (Google) gave a video presentation to the conference. Vint Cerf has famously likened the depletion of the IPv4 address space to running out of oil.

“Running out of IP addresses is like running out of oil”, Vint Cerf, 2004.

Tony Hain (Cisco) showed just how close we are to running out of IPv4 addresses. He and others predict the exhaustion of the central pool of IPv4 addresses will occur between 2009 and 2011. He showed that in the final stages of address exhaustion there will be a rush for the remaining address space thereby speeding up the process of address depletion.

In order to manage the final stages of the depletion of the IPv4 address pool regional registries (RIRs) are modifying their address policies. Miwa Fujii (APNIC) summarises the recent APNIC meeting in New Zealand and the key policy changes that were made there. In particular, two important polices seek to improve the management of IPv4 address space. One reserves an address block for the IPv6 transition. This policy seeks to avoid the situation where there are no IPv4 addresses left for use with IPv6 transition technologies making migration to IPv6 even harder. Another policy immediately reserves one block for each regional registrar so that each registrar will have at least one block assigned to it when all other blocks have been assigned.

One effect of both of these policies is that they allocate some of the remaining pool of IPv4 addresses. This means that the predicted date for the central address pool to be deleted has been brought nearer. Despite this, no one is likely to argue that these policies are anything other than a good idea.

The conference was a resounding success. It is clear that the take up of IPv6 is increasing and that the world is becoming aware of the need to migrate to IPv6 before all of the IPv4 addresses have finally been assigned.

At lot can happen in a year. This is certainly true of IPv6 and Samba. In this article, I summarise the progress made in IPv6 enabling Samba and review the current status of Samba and IPv6 support. Further details can be found in my presentation Configuring Samba 3/4 for IPv6 Operation with Windows Server 2008 and Windows Vista.

Last year in my presentation at SambaXP 2007 (see SambaXP IPv6 Presentation) I showed how important it was that Samba catch up with Microsoft Windows in supporting IPv6. Microsoft’s latest operating systems, Windows Vista and Windows Server 2008 (then codenamed Longhorn) are IPv6 enabled by default. The increasing drive to implement IPv6 in various parts of the world meant that Samba risked being kept out of, or dropped from, environments where IPv6 is required.

Since then a lot has changed. Here are some highlights from the last twelve months:

• First ever Linux CIFS client mount over IPv6 to Windows Server 2008
• First ever file sharing over IPv6 with Windows Server 2008 and Windows Vista using Samba 4
• First ever join over IPv6 of Windows Server 2008 to a Samba 4 domain
• Samba 3.2 is IPv6 enabled
• First ever join of Samba 3.2 to a Windows Server 2008 domain over IPv6
• Experimental IPv6 name resolution enabled in the Linux CIFS client mount.cifs command

Erion is proud to have carried out each of these firsts and being involved with Jermey Allison in IPv6 enabling Samba 3.2.

Linux CIFS Client

The Linux CIFS client has full support for IPv6 in the Linux kernel. This kernel is now widely available in the latest releases of many Linux distributions. At present, the mount command mount.cifs does not support IPv6 name resolution and the IPv6 address must be specified using a mount option. However, my patch to mount.cifs enables IPv6 name resolution. During Samba XP, I worked with Steve French and Jelmer Vernooij to improve support for IPv6 in mount.cifs. Friday evening found Jelmer still working on rewriting mount.cifs to include IPv6 support.

Samba 3.2

As Samba 3.2 nears a production release, it has been fully IPv6 enabled. This was a result of my presentation at CIFS Engineering Workshop held at Google last year. Erion has carried out the IPv6 testing for Samba 3.2. This has gone well and very few bugs have been found. During SambaXP Jeremy Allison put in time to investigate and resolve IPv6 bugs in Samba 3.2. Further information on IPv6 enabling Samba 3.2 can be found in our presentations from the Google IPv6 Conference earlier this year.

Samba 4

Support for IPv6 in Samba 4 still relies on my hack (a new version of which can be found here). The interest in IPv6 shown by the Samba team is illustrated by the time I spent with Andrew Tridgell. Andrew was very keen to incorporate my patch into the standard build of Samba 4. This would mean that, where possible, Samba 4 would build with IPv6 support as standard. The work was not completed by the end of SambaXP, but I will be chasing Andrew to complete it over the next few weeks.

In conclusion, SambaXP 2008 was a very positive event for IPv6 support in Samba. Much work still has to be done, but in the very near future there will be a solution for those who wish to upgrade Samba 3.0 to Samba 3.2 in order to get IPv6 support. So far most of the IPv6 testing of Samba has been undertaken by Erion. I would be very interested to hear of anyone else who is testing or even using Samba over IPv6 in live environments. During the conference Jelmer migrated his use of the Linux CIFS client in his home network to operate over IPv6! Now for the rest of the world…

The Samba team have released a new preview version of Samba 3.2. This version includes the changes that Jeremy Allision made to enable IPv6 support in Samba 3.2.

At last year CIFS workshop at Google, Erion’s David Holder gave a presentation on how to IPv6 enable Samba. As a result Jeremy took up the challenge to IPv6 enable Samba 3.2 in “three weeks”. Jeremy succeeded.

Erion’s testing of the IPv6 enabled version of Samba 3.2 produced very good results. A few minor changes were required in order to allow Samba 3.2 to join a Windows Server 2008 domain. Finally, in January 2008, Erion’s David Holder made the first ever IPv6 join to a Windows Server 2008 AD domain using Samba 3.2.

The presentation on IPv6 in Windows given by Erion’s David Holder at Google’s IPv6 conference is now available for viewing on YouTube. This talk covers the status of IPv6 on Windows and some key things that you need to know if you are working with IPv6 on Windows Vista or Windows Server 2008.

You can view the talk at by clicking here.

This week Erion’s David Holder spoke at an IPv6 conference at Google. The presentation was enititled IPv6 on Windows. It covered the status of IPv6 on Windows Server 2008 and Windows Vista as well as pointing out some of the details that you need to be aware of as Windows administrators and developers.

The slides are available for download here IPv6 on Windows.

Erion’s David Holder has written a short how-to for those who wish to use the Linux CIFS client over IPv6. These instructions allow you to mount CIFS shares over IPv6 from Windows Vista, Windows Server 2008 and other IPv6 enabled CIFS servers.

Microsoft’s Sam Ramji interviewed Erion’s David Holder for a podcast on IPv6 and Samba. Full details can be found at http://port25.technet.com/archive/2007/05/31/samba-ipv6-and-windows-linux-interoperability-sam-interviews-dr-david-holder.aspx.