IPv6 has been a hot topic in the networking industry for over a year now, and as the changeover progresses, it is still a priority for companies. There are two main issues for IT departments.
The first is licensing. Some Cisco network devices will need an IOS (the Cisco Internetwork Operating System) licence upgrade to gain access to IPv6 features, which can raise the cost of a device considerably.
The second issue is performance. Some hardware-based forwarding platforms do not support IPv6 in hardware, leading to very poor IPv6 performance.
It is also highly advisable for companies to conduct a thorough network assessment by an independent third party to determine which equipment doesn’t need upgrading, which should be upgraded and which should be disposed of. The assessment would include an analysis of long-range planning that best reflects your organisation’s business needs, budget parameters, network capabilities and equipment support strategies.
A network audit from a reputable third party, one with no supplier bias, can help create a blueprint that pinpoints your challenges and addresses current operations while providing recommendations for future moves. This audit can determine over what time period the upgrade needs to happen – whether it’s in three months, six months or a year – and remove time pressures.
Read more about IPv6
Disposing of old equipment
If businesses need to upgrade to IPv6 and some of the equipment cannot be upgraded, it is worth remembering that there are still companies that might not need IPv6, but still need to maintain existing equipment.
By selling the technology they no longer need to an independent reseller, businesses can not only make some money, but also enable another company to replace older parts that companies such as Cisco no longer provide.
No need to upgrade
Network equipment manufacturers have seen this as an opportunity to push businesses towards immediate and costly upgrades, even if they are not really necessary.
It is important that companies resist this pressure as the majority of network gear has had IPv6 capability for years. For example, many existing L3 network switches from Cisco support IPv6 in hardware and don't require additional IOS licensing.
However, some equipment will not provide hardware forwarding of IPv6 data and would result in poor IPv6 performance. Below is a list of devices that support IPv6 in hardware and do not require additional IOS licensing for this support.
Device compatibility with IPv6
When we discuss IPv6 support in switches, we are discussing L3 switches. Switching functionality is performed via MAC address, and as such, any switch model will be able to switch IPv6 packets in hardware. Routing functionality is where IPv6 support comes into play.
All Catalyst 3560/3750 switches have hardware support for IPv6 forwarding, and starting in IOS version 12.2(50) SE, all IOS versions for these switches now support IPv6, including IPBASE.
In the Catalyst 4500 line, IPv6 forwarding in hardware is found on the WS-X45-Sup6-E and WS-X45-SUP6L-E supervisors, and like Cisco’s other current L3 switching platforms, IPv6 features are found in IPBASE. Beware, though, as older supervisors do not provide hardware forwarding of IPv6 data, resulting in very poor IPv6 performance.
The Catalyst 4900M and Catalyst 4948E switches are IPv6-capable platforms. Both of these switches support IPv6 in all IOS images, so there is no need for an additional IOS licence. Like the 4500, though, the older WS-C4948 and WS-C4948-10GE switches do not provide IPv6 forwarding in hardware.
Starting in IOS version 12.2(33)SXI, Cisco added IPv6 features to all IOS versions, including IPBASE and IP Services. The Catalyst 6500, with its large amount of hardware forwarding resources, is very well-suited for demanding IPv4 and IPv6 environments, especially when deployed with a Sup720-3BXL or VS-S720-10G-3CXL. However, the still popular Sup2 does not support IPv6 in hardware, making it completely unsuitable for an IPv6 deployment.
Glenn Fassett is general manager, international, at Network Hardware Resale
This was first published in February 2012