The problem is that every one reuses the same RFC1918 space and this becomes a problem when you join them all together. For instance I discovered this year there is a electronic payments processor here in Australia that uses the 29/8 space. I'm doing a project for a large retail company that has to route payments to lots of providers. Each one has a different way of handling the conflict - either through properly registered public space, or through NATting to their own or the customers space. I did raise the issue that 29/8 was now actually routable on the internet, and maybe the provider should pick another strategy. But I don't think they see it as an issue mainly because these networks are quite closed and separated from regular internet space
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The problem is that every one reuses the same RFC1918 space and this becomes a problem when you join them all together. For instance I discovered this year there is a electronic payments processor here in Australia that uses the 29/8 space. I'm doing a project for a large retail company that has to route payments to lots of providers. Each one has a different way of handling the conflict - either through properly registered public space, or through NATting to their own or the customers space. I did raise the issue that 29/8 was now actually routable on the internet, and maybe the provider should pick another strategy. But I don't think they see it as an issue mainly because these networks are quite closed and separated from regular internet space