i want to create a Gameserver in a Windows VM on my Ubuntu 16.04 Server with KVM.

I have already installed the vm and it is running properly. I deactivated the Windows Firewall directly in the VM.

The Windows VM communicates via a network bridge with the Internet that also works.

For my server I have released these ports in the Ubuntu Firewall ( Iptables ):

TCP: 2302,27015-27030,27036-27037
UDP: 2302,4380,27000-27031,27036

I realized the port forwarding according to these instructions: https://www.cyberciti.biz/faq/kvm-forward-ports-to-guests-vm-with-ufw-on-linux/

an iptables -L FORWARD -nv --line-number retun this:

root@s1 ~ # iptables -L FORWARD -nv --line-number
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
num   pkts bytes target     prot opt in     out     source               destination
1     2532  201K ACCEPT     all  --  *      virbr0       ctstate RELATED,ESTABLISHED
2     5720  842K ACCEPT     all  --  virbr0 *
3        0     0 ACCEPT     all  --  virbr0 virbr0  
4        0     0 REJECT     all  --  *      virbr0              reject-with icmp-port-unreachable
5        0     0 REJECT     all  --  virbr0 *              reject-with icmp-port-unreachable
6        0     0 ACCEPT     all  --  *      virbr0     state NEW,RELATED,ESTABLISHED

an iptables-save -t filter | grep FORWARD retun this:

root@s1 ~ # iptables-save -t filter | grep FORWARD
-A FORWARD -d -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -s -i virbr0 -j ACCEPT
-A FORWARD -i virbr0 -o virbr0 -j ACCEPT
-A FORWARD -o virbr0 -j REJECT --reject-with icmp-port-unreachable
-A FORWARD -i virbr0 -j REJECT --reject-with icmp-port-unreachable
-A FORWARD -s -d -o virbr0 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT

My networ interface looks like this:

### Hetzner Online GmbH installimage

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback
iface lo inet6 loopback

auto br0
iface br0 inet static
  address <My Address>
  gateway <Another Address>
  # route <Another Address> via <Another Address>
  up route add -net <Another Address> netmask gw <Another Address> dev eth0
  bridge_ports eth0
  bridge_stp off
  bridge_fd 0
  bridge_maxwait 0
iface br0 inet6 auto

iface eth0 inet6 static
  address <Another Address>
  netmask 64
  gateway <Another Address>

It actually looks good for me, but I don't have that much experience with kvm yet, because when I try to connect to the game server, the client doesn't... I guess there is still a problem with port forwarding.

Is there anyone who can give me a hint? Thank you :)

--- EDIT ---

The Ip address of my Windows VM:

  • are you launching a game's server on you ubuntu server on which you are also launching a windows vm which should connect to the game server? – tatsu Jul 15 '19 at 12:39
  • @tatsu thx for reply i start a dayz Server, dayz only run on windows, so i have create a vm via kvm on my ubuntu server, and now i want to connect to my running game server via my pc – Rudi Jul 15 '19 at 12:51
  • yeah it seems normal to me that you can't connect to a server that shares the same IP as your client. also running this from a VM is precarious at best. I strongly recommend you buy a small NAS and run your dayz server on that. it'll be better for you and for your friends. – tatsu Jul 15 '19 at 13:05
  • @tatsu its not the same server, i have a ubuntu server, on this mashine runs a windows vm with the server. I want to connect with my private pc not the ubuntu server, to the server in the vm – Rudi Jul 15 '19 at 13:07
  • ok then the problem is the whole vm aspect. I don't know what is causing the issue then. – tatsu Jul 15 '19 at 13:11

after days of searching, i found out that my server running in the windows VM needed more ports than i released - i released all the ones i found in the docu... -.

If you start with KVM VM´s and want to connect to VM´s from the internet, then configure a bridged network in which you combine your network interface. After that the VM´s will be managed as devices in a NAT network.

Then these instructions can be used to realize the port forwarding from the Internet to the port of the Vm:


The VM is created in this way:

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