In a message written on Mon, Aug 06, 2012 at 10:05:30AM -0500, Chris Boyd wrote:
Speaking as someone who does a lot of work supporting small business IT, I suspect the number is much lower. As a group, these customers tend to be extremely cost averse. Paying for a secondary access circuit may become important as cloud applications become more critical for the market segment, but existing smart NAT boxes that detect primary upstream failure and switch over to a secondary ISP will work for many cases. Yes, it's ugly, but it gets them reconnected to the off-site email server and the payment card gateway.
I don't even think the dual-uplink NAT box is that ugly of a solution. Sure it's outbound only, but for a lot of applications that's fine. However, it causes me to ask a differnet question, how will this work in IPv6? Does anyone make a dual-uplink IPv6 aware device? Ideally it would use DHCP-PD to get prefixes from two upstream providers and would make both available on the local LAN. Conceptually it would then be easy to policy route traffic to the correct provider. But of course the problem comes down to the host, it now needs to know how to switch between source addresses in some meaningful way, and the router needs to be able to signal it. As messy as IPv4 NAT is, it seems like a case where IPv6 NAT might be a relatively clean solution. Are there other deployable, or nearly deployable solutions? -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/