VirtualBox Scenario internal DNS with private IP

[Coffee]

Hello.

I'm new with Ubuntu / VirtualBox.
I'm running Ubuntu 16.04 as host os on a notebook with
Intel® Core™ i5-6200U CPU @ 2.30GHz × 4
with VirtualBox Version 5.1.10 r112026 (Qt5.5.1) in Dec. 2016 and now
with VirtualBox Version 5.1.14 r112924 (Qt5.5.1) in Feb. 2017 .

Two from three guest systems run as expected
a) Ubuntu 14.04 guest ok = gets private IP from DHCP - private DNS
b) Ubuntu 16.04 guest ok = gets private IP from DHCP - private DNS
c) WIN10 guest not ok = gets public IP - doesn't get info from DHCP - private DNS
d) Ubuntu 16.04 host ok = gets private IP from DHCP - private DNS ( even though it still has IPv6 )

Scenario is as follows:
I'm running a Synology DiskStation 216 with auto update at home.
To get the private IP for my Diskstation's URL I run the Synology DNS server and the Synology DHCP server to deliver the private IP of the Diskstation to systems in my home network. I've turned off IPv6 on my WIN10 PC and on my 3 VB guest systems to get this running. This works fine with one exception: The WIN10 guest does not get the private IP of my DiskStation's URL offered by my private DNS but gets the public IP from the public DNS

I'm using LAN with cable, no WLAN yet, because I want not yet to touch VirtualBox & WLAN - issues at the time beeing.
All guests (Ubuntu 14.04, 16.04 and WIN10) are set to NAT as network.

Any suggestions, questions or comments what I should do to hand over the private IP from my private DNS to the WIN10 guest as well?

Best regards,
Coffee, Germany

[mpack]

Perhaps if you told us a little more about the VirtualBox-relevant parts of the story, e.g. which VirtualBox networking mode are you using? I assume you are using bridged networking?

Windows 10 may have flagged your network connection as suspect. This has been something Windows does since Vista: Google for "windows unidentified network".

Also, just on a point of jargon, the phrase "private IP" makes my head hurt! (likewise public IP). ISTM your IP can't be private if you want other devices to be able to talk to you. As I understand it you seem to be describing a standard LAN, with or without a gateway to the outside (WAN) world.

[Coffee]

Hello again,

guess I found the Root Cause of the problem I was talking about when I googled for "DNS from 127.0.1.1" : Root cause seems to be the Dnsmasq https://en.wikipedia.org/wiki/Dnsmasq in my Ubuntu 16.04 host as well as in the 14.04 and 16.04 guests. Reading https://forum.ubuntuusers.de/topic/dns- ... st-6509377 made me try to deactivate the

Code: Select all

dns=dnsmasq

in the default content of the

Code: Select all

/etc/NetworkManager/NetworkManager.conf

file using

Code: Select all

sudo nano /etc/NetworkManager/NetworkManager.conf

and made it look as follows:

Code: Select all

[main]
plugins=ifupdown,keyfile,ofono
#dns=dnsmasq

[ifupdown]
managed=false

I restarted host an guests after these changes because I'm not yet familiar with commands like killall, service restart and cat. I did this in the 16.04 host as well as in the 14.04 and the 16.04 guest. My first impression is that it solves my problem nicely when I use a LAN cable to connect my notebook to my LAN. When I use WLAN the DNS response times vary a lot: sometimes perfectly fast, sometimes time outs. But it's fair enough for me at the moment and I can continue to learn more about Ubuntu and Virtualbox .

Best regards,
Coffee, Germany

P.S.:
Perhaps https://en.wikipedia.org/wiki/Private_network helps against headaches caused by my "private IP" jargon . To enable communication between devices with private IPs in different networks, Network address translation (NAT) https://en.wikipedia.org/wiki/Network_a ... ranslation is used on the router / firewall between either two different private networks or between a private network and the InTERnet.