virtualbox.org

TL;DR Guests on one server can't connect while guests on the other server can. Both NAT and Bridged adapter tried.

I'm completely out of ideas, let me start by describing my issue, followed by the network and finally the things I've tried and some common questions you might ask.


I have two servers who both run Virtualbox.
Let's call these servers server A and server B.
Server A*:
- runs 5.2.4 r119785
- Ubuntu 16.04
- Host has perfect access both internal and external.
- Guests no internet, perfect connection to gateway and internal network

Server B:
- runs 5.0.40_Ubuntu r115130
- Ubuntu 16.04
- Host has perfect access both internal and external.
- Guests perfect connection

Server A* is facing some issues whilst Server B has none. Astrix will indicate what one of a list is having the issue (for easier reading)
Server A*s' guests used to have perfect internet connection but after a power outage (no issues) virtualbox started to display this error.

PLEASE NOTE:
- All servers do not have any firewall rules. (iptables -S shows only default rules (ALLOW))
- Even the ones usually requiring them for a DMZ

Network & Gateways:
Internal Network: 192.168.178.0/24
- 192.168.178.1
Internal Network (DMZ): 10.0.0.0/8
- 10.0.0.1

Server A*:
- 192.168.178.12

Server B:
- 192.168.178.11


So again, Server A has no issues but the guests do.
I've enabled both NAT and bridged adapter to troubleshoot Server A*'s machines, In the end only NAT will be enabled.
Cable is connected for every adapter.
Both NAT and Bridged adapters are correctly set up with DHCP

Server A* Guest 1: (No internet)
- 10.1.0.1
- 10.0.3.15 (NAT)
- 192.168.178.114 (Bridge)

Server A* Guest 2: (No internet)
- 10.0.1.1
- 10.0.3.15 (NAT)
- 192.168.178.114 (Bridge)


Server B Guest 1 (VPN Gateway): (Internet)
- 10.10.0.1 (10.10.0.0/16 VPN gateway)
- 10.0.0.200 (DMZ)
- 192.168.178.200 (Internal)

Cans and Can'ts

Server A's Guests can't:
- nslookup google com
. ping google com
- ping 8.8.8.8
- ping {public_home_ip}

Server A's Guests can:
- ping 192.168.178.1
- ping 192.168.178.11 (B)
- ping 192.168.178.12 (A*)
- ping 10.0.0.200
- ping 10.0.0.1


Server B's Guests can:
- ping 192.168.178.1
- ping 192.168.178.11 (B)
- ping 192.168.178.12 (A*)
- ping 10.0.0.200
- ping 10.0.0.1
- nslookup google com
. ping google com
- ping 8.8.8.8
- ping {public_home_ip}


Things I've tried:
I've tried rotating the MAC address
I've tried reinstalling VBox
I've tried upgrading VBox (which is why it's the most recent version)
I've tried restarting the host
I've tried restarting the guests
I've tried temporarily turning off the adapters
I've tried modifying promiscuous mode
I've tried changing the adapter type


I hope this gives enough insight into my issue.

Any kind of help would be appreciated

ANY KIND OF HELP WOULD BE APPRECIATED

You know why *I* didn't even try to reply? I didn't even read it. TL;DR...
Can you provide an "executive summary" of the problem is? Then you get into the details, on a need-to-know basis.

I have a machine that hosts VM's with Virtualbox, the VM's used to obtain internet via both NAT and Bridged Adapter, however, due to an unkown change it no longer works.
The VMs on the machine no longer have internet.

I did actually include a TL;DR at the bottom of the post

So the working host runs Ubuntu 16.04 and VirtualBox 5.0.40 and the failing one runs the same version of Ubuntu and VirtualBox 5.2.4.

If it were me then I would start by upgrading it to 5.2.6 along with corresponding version of extension pack and 5.2.7 guest additions (not that I could see which guest OS you are using)

If that doesn't work then upload a zipped version of the log file for the guest that isn't working as you expect along with the output of:

ipconfig /all or ifconfig -a
dmesg (if it is a Linux guest)

-Andy.

Host dmesg: http://termbin.com/m2j8 (has internet)
Guest dmesg: https://pastebin.com/sETUrjn7 (no internet)
Guest ifconfig: https://pastebin.com/EZPGM7y2 (no internet)