On 2008/01/09 11:04, Stiphane Chausson wrote: > In a [1]press communiqui (in french, sorry)
http://signal.eu.org/blog/2007/12/12/ipv6-chez-free/ is informative too. (this is also in french). > they say they give 2^64 ip address to every customer. > To me, total ipv6 beginner, it seems a lot ! > What is bad with "/64" ? rfc4291 says: For all unicast addresses, except those that start with the binary value 000, Interface IDs are required to be 64 bits long and to be constructed in Modified EUI-64 format. so if you further divide a /64 into multiple subnets you aren't compliant with the standards, and you break the usual ipv6 address autoconfiguration method. the current _guidelines_ (not requirements) for allocations to subscribers are given in rfc3177: [...] - /48 in the general case, except for very large subscribers - /64 when it is known that one and only one subnet is needed by design - /128 when it is absolutely known that one and only one device is connecting. In particular, we recommend: - Home network subscribers, connecting through on-demand or always-on connections should receive a /48. - Small and large enterprises should receive a /48. - Very large subscribers could receive a /47 or slightly shorter prefix, or multiple /48's. - Mobile networks, such as vehicles or mobile phones with an additional network interface (such as bluetooth or 802.11b) should receive a static /64 prefix to allow the connection of multiple devices through one subnet. - A single PC, with no additional need to subnet, dialing-up from a hotel room may receive its /128 IPv6 address for a PPP style connection as part of a /64 prefix. Note that there seems to be little benefit in not giving a /48 if future growth is anticipated. In the following, we give the arguments for a uniform use of /48 and then demonstrate that it is entirely compatible with responsible stewardship of the total IPv6 address space. [...] there are some suggestions out (see recent nanog posts) that /56 be used for private consumer subscribers, though this is probably not useful for all but the largest consumer ISPs.
