Upgrading from 1.1.8 to 1.2.0 version 201904151631, it seems that in service dhcp-server the authoritative enable is missing, and is not replaced with authoritative as it would happen if configured manually; the following is the relevant diff between the before-upgrade and after manually re-enabling the authoritative option (diff -U10 -w ./config.boot.2019-04-15-1740.pre-migration ./config.boot) (i.e. the authoritative line is missing from the automatically migrated file):
` service { dhcp-server { - disabled false shared-network-name ******** { - authoritative enable + authoritative subnet ********/24 { `
(I've originally submitted this to the VyOS forum: https://forum.vyos.io/t/issues-encountered-while-upgrading-from-1-1-8-to-1-2-0-201904151631/3635)