Prefix Translation - HP FlexNetwork MSR2003 Configuration Manual

NO-PAT
NO-PAT translates an IPv6 address to an IPv4 address. The IPv4 address cannot be used by
another IPv6 host until it is released.
NO-PAT supports all IP packets.
PAT
PAT translates multiple IPv6 addresses to a single IPv4 address by mapping the IPv6 address and
source port to the IPv4 address and a unique port. PAT supports the following packet types:
•
TCP packets.
•
UDP packets.
•
ICMPv6 echo request and echo reply messages.

Prefix translation

NAT64 prefix translation
NAT64 prefix is an IPv6 address prefix used to construct an IPv6 address representing an IPv4 node
in an IPv6 network. No IPv6 host uses a constructed IPv6 address as its real IP address. The length
of a NAT64 prefix can be 32, 40, 48, 56, 64, or 96.
As shown in
•
If the prefix length is 32, 64, or 96 bits, the IPv4 address is embedded as a whole.
•
If the prefix length is 40, 48, or 56 bits, the IPv4 address is separated by bits 64 through 71 in an
IPv6 address.
Figure 156 IPv6 address construction with NAT 64 prefix and IPv4 address
AFT uses a NAT64 prefix to perform the following translation:
•
IPv4-to-IPv6 source address translation. AFT translates a source IPv4 address to an IPv6
address constructed by using the NAT64 prefix and the IPv4 address.
•
IPv6-to-IPv4 destination address translation. AFT uses the NAT64 prefix to match destination
IPv6 addresses and extracts the embedded IPv4 address from matching IPv6 addresses.
IVI prefix translation
An IVI prefix is a 32-bit IPv6 address prefix. An IVI address is the IPv6 address that an IPv6 node
actually uses. As shown in
Figure 157 IVI address format
Figure 156, the construction methods vary depending on the NAT64 prefix length.
Figure 157, the IVI address includes an IVI prefix and an IPv4 address.
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