DHCPv6-PD doesn't work. DHCPv6-server won't start after commiting configuration

[Dmitry]

Yes, confirmed. Looks like it is know issue with missing prefix validation

Dhcpv6 pd example? error "network mask too short"

This works for me: configure set interfaces ethernet eth0 address 2001:db8::1/64 set service dhcpv6-server shared-network-name LAN subnet 2001:db8::/64 prefix-delegation start 2001:db8:1:: stop 2001:db8:1:fff0:: set service dhcpv6-server shared-network-name LAN subnet 2001:db8::/64 prefix-delegation start 2001:db8:1:: prefix-length 60 commit exit Note that the stop address is inclusive.

https://phabricator.vyos.net/T3493