I have implemented nat66 in vyos 1.3, but it cannot be merged at present, and the prerequisite for merging must be vyos to upgrade to 5.8 linux kernel, please refer to https://phabricator.vyos.net/T2518, if you must support it now nat66, please find me in the slack workspace, but I must say that nat66 in the 4.19 linux kernel will modify the interface identifier