Juniper JUNOSE SOFTWARE 11.0.X - BROADBAND ACCESS CONFIGURATION GUIDE 4-1-2010 Configuration Manual page 142

JUNOSe 11.0.x Broadband Access Configuration Guide
Keep the following points in mind when you configure IPv6 local address pools to
assign prefixes to requesting routers:
102
DHCPv6 Local Address Pools for Allocation of IPv6 Prefixes Overview
You must enable the IPv6 local address pool feature to be able to configure IPv6
local address pools.
You can configure IPv6 local address pools for DHCP to allocate prefixes to client
requests that are received over PPP or non-PPP links, such as VLAN, S-VLAN, or
Ethernet.
You can configure multiple local address pools on a single virtual router, up to
a maximum of 500 pools per virtual router.
You can also configure multiple address pools on multiple virtual routers. Each
IPv6 local address pool must have a unique name.
You can configure a valid and preferred lifetime for each IPv6 prefix, which
determines the length of time the requesting router can use the prefix.
You can configure multiple prefix ranges in an IPv6 local pool. The ranges can
have the same or different assigned prefix lengths.
You cannot configure overlapping prefix ranges in an IPv6 local pool. If you try
to configure a prefix range that overlaps with an existing prefix range in the IPv6
local pool, an error message is displayed stating that the prefix range could not
be configured. Similarly, an error message is displayed if you try to configure a
prefix range in an IPv6 local pool that overlaps with a prefix range in another
IPv6 local pool on the same virtual router.
You can configure certain prefix ranges to be excluded from being used for
delegation to the requesting router.
You can configure the IPv6 addresses of a primary and secondary DNS server
in an IPv6 local pool. The DNS server addresses are returned to the client in
DHCPv6 responses as part of the DNS Recursive Name Server option.
You can configure a list of up to four domain names in an IPv6 local pool to be
used during the resolution of hostnames to IP addresses. These domain names
are returned to clients in the DHCPv6 responses as part of the Domain Search
List option.
You can configure an IPv6 local address pool in an AAA domain map to assign
prefixes to requesting DHCPv6 clients using the ipv6 prefix-pool-name command
in Domain Map Configuration mode. If the authentication server returns the IPv6
local address pool name in the Framed-IPv6-Pool attribute of the
RADIUS-Access-Accept message, this pool overrides the IPv6 local address pool
configured in the domain map.
You cannot delete a pool or a prefix range from which prefixes have been
allocated to requesting routers or DHCPv6 clients. However, you can forcibly
delete such a pool or prefix range by using the force keyword in the ipv6 local
pool poolName and prefix commands. If a pool is deleted or the prefix range
associated with the pool is deleted, and prefixes have been assigned to DHCPv6
clients or requesting routers, the corresponding DHCPv6 bindings are also deleted.
When multiple prefix ranges are configured in a pool, the DHCPv6 prefix
delegation feature allocates prefixes from the configured ranges in the order of
the assigned prefix length. The delegating router or the DHCv6 server attempts
to allocate a prefix from the range with lowest assigned prefix length. If this
attempt fails because the pool has been fully allocated, the server tries to allocate