I've just cross-graded from a erl running 1.8.0 to a erx running 1.9.1.
I copied my config across (in as much as that's possible), and almost everything appears to be fine......
....except the dhcp server isn't setting the domain-name suffix in a way usable by Windows or Linux. As far as I can tell at some point (recently I assume), /opt/vyatta/sbin/dhcpd-config.pl was changed to take the variable called "Domain" in the gui ("domain-name" in the cli), and instead of setting that directly as "option domain-name" it now assumes the configured variable is a space delimited list of domain names and then sets "option domain-search" instead.
Unfortunately "option domain-search" doesn't seem to work, certainly on none of my systems (linux, android, Windows) were happy with it.
I don't see a problem setting "option domain-search", but please can it also set "option domain-name" ?
when I set "option domain-name" by hand editing /opt/vyatta/etc/dhcpd.conf my problem is solved, but that is a pretty temporary setting.
my show version for info:
Version: v1.9.1 Build ID: 4939092 Build on: 12/14/16 07:02 Copyright: 2012-2016 Ubiquiti Networks, Inc. HW model: EdgeRouter X 5-Port