There's an ongoing "panic" all over the news for some time now about IPv4 running out and IPv6 being the savior. All the big companies are preparing and showing how it should be done (last actions from Google, FaceBook). I do understand the problem and I do think people should slowly starting to move but is it also a big deal for small companies?
I've clients which are usually very small companies with 5 to 50 employees using Windows XP/Windows 7 for their clients and Windows 2003/Windows 2008R2 for their servers. Nothing complicated with 1 up to 5 switches (some managed and some unmanaged but nothing too complicated - Linksys/D-Link). On top of it there's usually modem provided by ISP and small home router (D-Link, Draytek, Linksys) or if the client is a bit bigger something like FortiGate FW50B.
How should they prepare? Is there anything each company should do? Like buy new routers? I'm looking for general advice on how to approach this from my clients perspective. Should we wait for ISP to come to us first and then try to fix things later or there's nothing we should be worried about and just do what we do and there's nothing to be done ?
For a truly small company, just wait for your ISP, and anyone else who handles your public face : if you have hosted mail, they should handle any IPv6 matters for mail. If someone hosts your website, ask them if they have made IPv6 DNS entries for you, or what their plan for doing so is. If they say they don't have one, I wouldn't worry about it much this year. Maybe a little bit of worry next year, but it's too soon to say.
I'd be suprised if your ISP didn't offer IPv6 now. Small companies will have the easiest transition so I would get them started now. depending on the home router they have they may or may not have to purchase a new one. http://www.sixxs.net/wiki/Routers is a geat resource to get started on what home routers to look at.
I recall that ICANN recommended that everyone switch to IPv6 about oh, 15 years ago. So while you think that companies are "slowly" changing over this year, it's actually quite an abrupt and panicked change that's been brought about only because we're all in imminent danger of falling off the edge. The transition should have been completed by now, rather than just starting.
That said, two major obstacles currently stand in the way of complete transition today: SOHO routers (virtually none of which support IPv6) and last-mile ISPs. And they're basically stuck with a lack of demand from consumers, most of whom are completely ignorant of the problem. The ISPs could force the issue by switching to IPv6 for everyone tonight (or next month with sufficient warning), but without some kind of illegal collaboration between them, it would enrage their customers and force them to sign up for service with competing ISPs that haven't made the upgrade. In no small part because there are almost no SOHO routers on store shelves, and consumers wouldn't even have the choice.
I would do all the low-risk things before your ISP has native IPv6 ready.
Making sure that your devices have IPv6 enabled so that when you offer IPv6 to your network they accept the traffic. They should get local IPv6 addresses like fe80::21a:a0ff:fed1:5424 but no real addresses. This will help you find out if you have any rogue RA's.
Check all your routers and see if they have native IPv6 support. Check all appliances and find out if they have IPv6 support. Printers and NAS's are a good place to start looking. Give yourself a picture of the things that you will need IPv4 for the long term.
There are a few software updates you may need to perform in order to be ready for IPv6. Certain older versions of MacOS X and Opera are known to cause problems.