in my case there is an error on the Quick-start side of docs.vyos.io. It does not work: set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 name-server ‘192.168.0.1’
better: dns-server instead of name-server
(Version vyos-1.2.9-S1-amd64)
Docs for 1.2.9: Quick Start Guide — VyOS 1.2.x (crux) documentation It uses dns-server parameter!
I guess you were using docs for latest vyos version. Check in left bottom of the page, you can choose docs version.
Note that some commands have been moved and renamed between 1.2.x, 1.3.x and latest rolling 1.4.x.