On Mon, 31 Oct 2011, Dmitry Cherkasov wrote:
The problem we ran across is that ISP in US does not wish to accept prefixes longer then /48 from us. Need your advice: is this normal to distribute /48 by /56 parts across locations or should we obtain separate /48 for each of them? Or maybe we need /32 that can be split into multiple /48? Anyway we are not ISP so /48 looks quite reasonable and sufficient for all our needs.
Think of a /48 the same way you'd use a /24 of IPv4 space in a multi-homed design. /48 is the smallest v6 block that you can reasonably expect to be globally reachable. Many providers will not accept anything smaller, unless it's from one of their own blocks, in which case it will likely get aggregated into their larger prefix. jms