I found that the DHCPv6 server did not work after I upgraded. I executed the following command to report an error:
```
set interfaces ethernet eth1 address dhcpv6
```
The command will be wrong, easy to repeat!
In operation mode:
```
restart dhcpv6 server
```
The command reports the following errors:
```
Failed to restart isc-dhcpv6-server.service: Unit isc-dhcpv6-server.service not found.
```
Under the same configuration, my computer used to get the internal IPv6 address from vyos DHCPv6 and eui64. I don't know why, after upgrading vyos, IPv6 can't be obtained! It is suspected that there may be serious bugs in IPv6!