I found that the DHCPv6 server did not work after I upgraded. I executed the following command to report an error:
```bash
set interfaces ethernet eth1 address dhcpv6
```
The command will be wrong, easy to repeat!
In operation mode:
```bash
restart dhcpv6 server
```
The command reports the following errors:
```bash
Failed to restart isc-dhcpv6-server.service: Unit isc-dhcpv6-server.service not found.
```