For those who use NAT66, add the following commands:
Add destination and except prefix to Source NAT (for example):
```
vyos@vyos# set nat66 source rule 100
Possible completions:
description Rule description
> destination NAT destination parameters
disable Disable NAT66 rule
log NAT66 rule logging
outbound-interface Outbound interface of NAT66 traffic
> source IPv6 source prefix options
> translation Translated IPv6 address options
vyos@vyos# set nat66 source rule 100 source prefix
Possible completions:
<h:h:h:h:h:h:h:h/x> IPv6 prefix
!<h:h:h:h:h:h:h:h/x> Match everything except the specified IPv6 prefix
vyos@vyos# set nat66 source rule 100 destination prefix
Possible completions:
<h:h:h:h:h:h:h:h/x> IPv6 prefix
!<h:h:h:h:h:h:h:h/x> Match everything except the specified IPv6 prefix
```
Add source and except prefix to Destination NAT (for example):
```
vyos@vyos# set nat66 destination rule 100
Possible completions:
description Rule description
> destination IPv6 destination prefix options
disable Disable NAT66 rule
inbound-interface Inbound interface of NAT66 traffic
log NAT66 rule logging
> source NAT source parameters
> translation Translated IPv6 address options
vyos@vyos# set nat66 destination rule 100 source prefix
Possible completions:
<h:h:h:h:h:h:h:h/x> IPv6 prefix
!<h:h:h:h:h:h:h:h/x> Match everything except the specified IPv6 prefix
vyos@vyos# set nat66 destination rule 100 destination prefix
Possible completions:
<h:h:h:h:h:h:h:h/x> IPv6 pr
!<h:h:h:h:h:h:h:h/x> Match everything except the specified IPv6 prefix
```