Printer FriendlyEmail Article Link

What does it mean to have a DHCP-PD pool that looks like "pd_pool_1 2200:1::/64 80"?

Answer

This means that the DHCP-PD server has 2^16 prefixes (i.e., 80 - 64) that are 80 bits long that it can delegate to requesting DHCP-PD clients.

Here's is a simpler example using "pd_pool_1 2200:1::/60 64".

ipv6 dhcp pool dhcp_pd_pool_1
 prefix-delegation pool pd_pool_1
!
interface GigabitEthernet0/1
 duplex auto
 speed auto
 media-type rj45
 no negotiation auto
 ipv6 address 2200:1::1/64
 ipv6 enable
 ipv6 dhcp server dhcp_pd_pool_1
!
ipv6 local pool
pd_pool_1 2200:1::/60 64

In this case the 7200 as a DHCP-PD server will have a pool 4 bits "wide" (i.e., 64 - 60) from which to pull prefixes that it can delegate to requesting DHCP-PD clients. 

|0   16|17  32|33  48|49  60|61  64|
+------|------|------|------|------|
| 2200 : 0001 : 0000 : 000     0:: |
                               ^
                               |
                               +----4 bits for a pool of 16 prefixes

The prefixes would be:

  • 2200:0001:0000:0000::
  • 2200:0001:0000:0001::
  • 2200:0001:0000:0002::
  • ...
  • 2200:0001:0000:000e::
  • 2200:0001:0000:000f::

    or in more succinct notation
     
    • 2200:1::
    • 2200:1:0:1::
    • 2200:1:0:2::
    • ...
    • 2200:1:0:e::
    • 2200:1:0:f::

The requesting DHCP-PD clients will then have the remaining 64 bits of host addresses to assign to its hosts.

 


Product : Access,DHCP-PD