I'm installing Ubuntu 18.04 beta2 from server iso, it runs with the new subunquity installer, I set up the network, it reports that the settings are not correct, I don't know why they are not correct, see the screenshot. But the main bug is that I cannot continue installation with not working network.
See the same setting in another server with Ubuntu 16.04 (not with Netplan) in the same network, they do work:
$ cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
allow-hotplug ens3
iface ens3 inet static
address 62.109.6.71
netmask 255.255.255.255
gateway 10.0.0.1
pointtopoint 10.0.0.1
dns-nameservers 8.8.8.8 77.88.8.1
A screenshot of network settings in subunquity is attached. Now I'm installing a daily build iso, it uses the old installer.
ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: subiquity (not installed)
ProcVersionSignature: Ubuntu 4.15.0-17.18-generic 4.15.17
Uname: Linux 4.15.0-17-generic x86_64
ApportVersion: 2.20.9-0ubuntu5
Architecture: amd64
CurrentDesktop: XFCE
Date: Thu Apr 19 11:35:48 2018
InstallationDate: Installed on 2017-08-28 (233 days ago)
InstallationMedia: Xubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
SourcePackage: subiquity
UpgradeStatus: Upgraded to bionic on 2018-02-08 (69 days ago)
The issue seems to be that your subnet does not contain the gateway address, and that pointtopoint configurations aren't supported by the default server installer (as well as some of its dependencies, i would think).
The alternative server installer should work, but you may need to use it to install without networking, then (after booting into the installed system) apply a netplan configuration as discussed in bug 1767607 , comment #3