Datatek IPv6 Transformer User Manual - Manual (Page 19)

S E C T I O N 2 O V E R V I E W
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Configuration
The DNS Server address for the IPv6 network is either manually configured on the General
Setup form or may be served from a DHCPv6 Server as specified on the DHCPv6 client form.
DHCPv6 Client
The Transformer can be configured on the DHCPv6 client screen to act as a DHCPv6 client to
receive an IPv6 address for itself along with other host configuration parameters from a DHCPv6
server. The Transformer can also receive the IPv6 proxy address for the host.
DHCPv4 Server
The Transformer can be configured on the DHCPv4 server screen to act as a DHCPv4 server
to the IPv4 legacy device to provide the IPv4 legacy device with an IP address and other host
configurations. The IPv4 address that is served to the IPv4 legacy device is the IPv4 address that
was configured on the
Interface Setup screen. This DHCP feature satisfies those IPv4 devices
that do not store their own IPv4 addresses but require a DHCP Server to give one to them.
Passthrough
The legacy IPv4 device can talk to other IPv4 devices across the network. In pass-through, the
Transformer does not translate IPv4 packets, but maps the IPv4 address representing the host.
In the direction from the IPv4 legacy device towards the network, the legacy device only needs to
ensure its routing table contains an entry for the subnet or host address of the IPv4 destination
host and that the gateway or next hop for that subnet or host address is the Transformer’s host-
side interface address as configured on the
Interface Setup screen’s host-side Transformer
IPv4 address. IPv4 hosts on the network can talk to the legacy host by addressing the legacy
host with the Device IPv4 Address that was configured in the network-side section of the
Interface Setup screen.
This feature may be useful for situations where not all the IPv4 devices on a link can be moved
behind Transformers at one time. The devices then must be separated by placing some of the
IPv4 devices on the network-side of the Transformer and a single IPv4 device behind the
Transformer on the host-side. Pass-through is then used to enable communication between the
IPv4 device on the host-side and all the other IPv4 devices on the network-side.
Address Pool
The transformer configuration includes a range, or multiple ranges, of IPv4 addresses that it can
use to satisfy the need to map network-side IPv6 addresses to host-side IPv4 addresses. The
processes described above, in which new IPv6 addresses are added to the list of endpoints
reachable by the legacy host, requires a supply of IPv4 addresses available to combine, one-to-
one, in bindings of IPv6 addresses to IPv4 addresses. This supply is called the address pool.
The designated private IPv4 address ranges are the best choice to be used to supply the pool. But
it is required that IPv4 addresses in the address pool must be addresses that are not reachable on
the network side.