LNSes send RA every ~1 hour
Customers are allocated a /48 block of addresses - this is usually per customer, and so a customer with multiple circuits or sites will have a /64 allocated from the larger /48 block. A /48 contains 65536 /64's and a /64 subnet is 18 million trillion addresses.
(Here, CPE refers to the router belonging to the customer which is being used at their end of the broadband line.)
When the CPE logs in and negotiates PPP, we use IPV6CP to negotiate an interface identifier - this happens at the same time as IPCP happens to negotiate V4 connectivity. Once this has been negotiated,the CPE should perform an ICMPv6
router solicitation - our LNSes will then reply with a Router Advertisement in order to negotiate the [http://en.wikipedia.org/wiki/Link-local_address Link Local] address in the form of FE80::, and will be based on the MAC address of the interface.
At this stage, there should be basic IPv6 connectivity to link-local, and if static routes and manually assigned addresses in place you should have a working connection.
Optionally, if routes and addresses have not been configured statically, DHCPv6 can be used for automatic negotiation of the IPv6 WAN and LAN prefixes - using DHCPv6 is usually the default for our routers (i.e. the ZyXEL) that we supply.