An incremental approach was adopted by ISS for IPv6 deployment which involved the upgrade of first the UKERNA Access Point and the C&NLMAN infrastructure before moving on to address the University network.
Provider Network Deployment
With the UKERNA equipment being beyond our control (and upgraded separately: http://www.ja.net/development/ipv6/statustable.html), the most pressing issue was that of C&NLMAN connectivity. ISS determined that the most effective way to overcome the problem given the issues with Extreme networking equipment was to modify their existing configuration by introducing an additional device upstream of the BlackDiamond 6k to handle L3 (i.e. routing) functionality leaving the former as purely a L2 switch for which it is better suited in any case. The new device, a Juniper m7i, now handles the IP routing and is well suited to this role (with hardware support) thereby neatly sidestepping the problem. This process was completed as of December 2004 and so from that date native IPv6 connectivity was available into the University network.
University Backbone Deployment
The University upgrade followed a roughly parallel path to that of C&NLMAN as the infrastructure is similar. As such, the main issue faced was with the Computing Department employing a BlackDiamond 10k and so while the L3/L2 approach was followed across the majority of the University backbone, this device could not necessarily be circumvented in the same way.
Ironically, the BlackDiamond 10k claimed to have full IPv6 functionality but when this was explored by ISS, it soon became clear that a dual stack configuration opens significant security holes in the IPv4 stack and so was not a viable option (IPv6-only operation however was fine). An updated version of the firmware for this device is currently with ISS who are in the process of testing it ahead of the release and use within the network.
As a result, it was decided that the best solution to this was a temporary direct link into the Computing Department based on a Cisco 7206 that was available. This was connected directly to the Juniper m7i at the university BAR (Border Access Router) to circumvent the existing infrastructure until the remainder of the network (including the BlackDiamond 10k) has been upgraded and production IPv6 can be supported. This was achieved recently and as of April 2005 native IPv6 via the new infrastructure is now available into the Computing Department on a research basis. In the near future this will be used to replace the existing tunnelled connectivity, and be made available departmentwide. Figure 13-9 shows the current configuration of the university infrastructure.
Finally, as part of the continued upgrade process, the BlackDiamond 6k within the University network has now been replaced by a 10k. As such, once suitable firmware is available for the BlackDiamond 10k devices, the university infrastructure will be fully capable of supporting production dual stack from end-to-end across the backbone.