SIIT-DC: Dual Translation Mode
This document is a summary of the SIIT-DC: Dual Translation Mode (SIIT-DC-DTM) architecture, and a small walkthrough that builds it using Jool.
This is the sample architecture from RFC 7756 section 3.2:
It’s the same as SIIT-DC, except an isolated IPv4 island amidst the IPv6-only Data Centre has been added. ER will revert the translation done by BR so these nodes can seemingly natively communicate with the IPv4 Internet.
You need this if SIIT-DC doesn’t suffice because some application in the Data Centre either doesn’t support NAT (i.e., the lack of end-to-end transparency of IP addresses) or gets a flu whenever IPv6 is around.
This will be the expected packet flow (in addition to the ones in the SIIT-DC Architecture):
Start from the SIIT-DC configuration and add the following SIIT Jool setup on ER:
ethtoolcommands have been skipped here for the sake of reducing clutter. Please add them in any serviceable environments.
And the new server record on BR:
Of course, also make sure
2001:db8:3333::464:0/120 is routed towards ER’s IPv6 interface.