Generic IPv6 addressing scheme (number plan)

== Networks ==

=== Typical ===

32bt:prfx::/32              LIR-allocated /32 address prefix
32bt:prfx:site::/48         "site": sparsely allocated (per /44) org/site ID
32bt:prfx:site:p000::/52    "p":    physical network ID of network with VLANs
32bt:prfx:site:pvvv::/64    "vvv":  vlan ID, 12 bit, 4096 available (per .1q)
32bt:prfx:site:pp00::/56    "pp":   phys net ID of net with non-vlan subnets
32bt:prfx:site:ppss::/64    "ss":   subnet ID, 8 bit, 256 available

- Any "p" assigned will block the assignment of every p0_h <= "pp" <= pf_h.

- By design, the primary physical network will be assumed to be "p" = 0.
  The primary (e.g. largest) vlan of this network can be special cased as
  having "vvv" = 0, regardless of its actual vlan ID.

- As a result, the first non-vlan subnet (e.g. for direct cable point-to-point)
  available will be "pp" = 10_h, "ss" = 0, ergo "ppss" = 1000_h

=== VLAN per sub-site ===

Example use case: business centre with multiple commercial tenants.

32bt:prfx:site:vvv0::/60    "vvv":  vlan ID, 12 bit, 4096 available (per .1q)
32bt:prfx:site:vvvs::/64    "s":    subnet ID, 4 bit, 16 available

- The larger /60 would typically routed via 32bt:prfx:site:vvv0::2 in the
  first of the smaller /64's.


== Static IPs for hosts ==

"prefix": Assigned /64, per the above networks addressing scheme.

Point to point:

    prefix::1/128           Upstream router
    prefix::2/128           Downstream router

Network with hosts:

    prefix::1/128           Upstream router

Colocation network (special case: "p" = 0, "vvv" = 0)

    prefix::1/128           Upstream router
    prefix::h/128           "h": assigned host ID > 1 for colo-provider host
    prefix::1:h/128         "h": assigned host ID for virtual/dedicated/colo
    prefix::c:h/128         "c": customer's unique assigned number > 1
                            "h": customer-chosen host ID
    prefix::c:h:h/128       "c": customer that wants more space
                            (for "h" = deadbeef_h or cafebabe_h, probably,
                            but hopefully some smarter scheme...)

- Note that "c" is just encoded information. It is not a routable subnet, and
  is not portable across subnets.

- Use of the 9th and 10th octets is deliberately avoided because of the 7th bit
  for automatically configured addresses (RFC 4291), and to avoid any
  suggestion of prefixes longer than 64 bits (e.g. 2001:db8:20:0:a2::1).

== Examples ==

32bt:prfx::1, colo router for first site
32bt:prfx:0000:0000 : 0000:0000:0000:0001

    site    = 0
    p       = 0
    vvv     = 0
    h       = 1

32bt:prfx:10::1, colo router for second site
32bt:prfx:0010:0000 : 0000:0000:0000:0001

    site    = 10_h = 16_d
    p       = 0
    vvv     = 0
    h       = 1

32bt:prfx:10:7f:221:6aff:fe7f:8aa0, laptop on vlan 127
32bt:prfx:0010:007f : 0221:6aff:fe7f:8aa0

    site    = 10_h = 16_d
    p       = 0
    vvv     = 7f_h = 127_d
    mac48   = 00:21:6a:7f:8a:a0

32bt:prfx:0:28b::2, downstream router on vlan 651
32bt:prfx:0000:028b : 0000:0000:0000:0002

    site    = 0
    p       = 0
    vvv     = 28b_h = 651_d
    h       = 2

32bt:prfx:10:1000::1, upstream router on non-vlan subnet
32bt:prfx:0010:1000 : 0000:0000:0000:0001

    site    = 10_h = 16_d
    pp      = 10_h = 16_d
    ss      = 0
    h       = 1

32bt:prfx:10::2a:e, primary smtp server for customer 42
32bt:prfx:0010:0000 : 0000:0000:002a:000e

    site    = 10_h = 16_d
    p       = 0
    vvv     = 0
    c       = 2a_h = 42_d
    h       = e_h = 14_d