NAT64_PLATPFX
MPASS(cfg->flags & NAT64_PLATPFX);
NAT64_CLATPFX | NAT64_PLATPFX;
flags |= NAT64_PLATPFX;
if (flags & NAT64_PLATPFX) {
cfg->base.flags = (uc->flags & NAT64LSN_FLAGSMASK) | NAT64_PLATPFX;
cfg->base.flags = (uc->flags & NAT64STL_FLAGSMASK) | NAT64_PLATPFX;