Can't connect SPICE/VNC to VM in Fedora Server 41

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1

Hi people. Ofesad here from Argentina.
I have my personal home server running fedora 41, working fine.
I wanted to run a VM with Ubuntu.
I created the VM, changed to UEFI, mounted the iso, installed. Everything is good.
Took note of the VM IP (virtual network), enabled ports (5900,5901) in both the server and the virtual network interface.

On my Windows 10 laptop: Installed virtviewer, added it to the firewall and allow’d it and launched it.
Try’d to connect to the ip (spice://192.168.122.118:5900 or spice://192.168.122.118:5901) Unable to connect to the graphics server

Changed the network config on the VM to direct, so it will conect directly to my network, tryd to connect: same.

Added ports to the VM firewall (ubuntu).
Same.

I am missing something for sure.

Please advice.

2

The VM is on a NAT network. It can call out but you cannot call in.
Just like on a ipv4 home router.

What I do is add a bridge network device and configure my VMs to use the bridge. Now the VMs will get an ip address from your networks DHCP server. And you can use that address from your windows box.

3

Connecting to a SPICE/VNC display remotely requires the following:

  • Make it listen on all interfaces in the display settings.
  • Configure the ports statically if you have multiple VMs.
  • Add permissive firewall rules for the relevant ports.

Note that the service binds to the host interface, not the guest.

4

I did that too.
The sittuation is the same.

It gets an IP fron the router and I cant connect, same error.

Changed the network config of the VM:
model from virtio to e1000e and does the same.

Disabled the server firewall completely, same.

Clarely I am doing something wrong that I cant figure out.

Just to clarify: the VM can conect to the network (either bridge o direct) perfectly.

Ofesad.

6

Yup. Correct.

But I alredy try’d direct connection and bridge.
In both cases it gets an ip from my router (192.168.0.213), but still I am unable to connect.

Will do a tcpdump and disable the VM firewall and see whats happen

Ofesad

7

To be clear, you need to connect to the LAN IP of your Fedora server.
It doesn’t matter how you configure network on the guests.
This works even if the guests don’t have any NIC.

If the issue persists, check the output on the Fedora server:

sudo firewall-cmd --get-active-zones
sudo firewall-cmd --list-all
sudo ss -lnpAinet | grep -e qemu
sudo virsh list --all
sudo virsh dumpxml VM --xpath //graphics
8 
sudo firewall-cmd --get-active-zones

FedoraServer (default)
  interfaces: enp5s0
libvirt
  interfaces: virbr0

sudo firewall-cmd --list-all

FedoraServer (default, active)
  target: default
  ingress-priority: 0
  egress-priority: 0
  icmp-block-inversion: no
  interfaces: enp5s0
  sources:
  services: Deluged Delugedadmin SFTPGo SPICE Scrapydweb cockpit dhcpv6-client mysql samba ssh
  ports:
  protocols:
  forward: yes
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

sudo ss -lnpAinet | grep -e qemu

tcp   LISTEN 0      1                127.0.0.1:5900       0.0.0.0:*    users:(("qemu-system-x86",pid=4102,fd=40))
tcp   LISTEN 0      4096                 [::1]:5901          [::]:*    users:(("qemu-system-x86",pid=4102,fd=11))

sudo virsh list --all

 Id   Nombre                    Estado
--------------------------------------------
 1    ubuntu24.04-2025-2-21-B   running
 -    ubuntu24.04-2025-2-21     off

Sorry for the delay. Had to reinstall the entire server. The Raid1 nvme decided to fail. Probably due to me changing things to try to make this work lol.

ALSO, now I am trying to reinstall these VMs. It boots, shows the Ubuntu logo but it doesnt get into desktop or installer. ( mouse seems to show the X)

9

You missed the very first step:

  • Virtual Machine Manager > VM > :bulb:Show virtual hardware details > Display Spice > Details > Spice Server > Address > All interfaces > Apply
10

Errmmm… No such option on Cockpit ?

11

You can use Virtual Machine Manager or CLI:

export VM="ubuntu24.04-2025-2-21"
export LIBVIRT_DEFAULT_URI="qemu:///system"
export EDITOR="sed -i -e \"/listen/s/'127\.0\.0\.1'/'0.0.0.0'/\""
virsh shutdown ${VM}
virsh edit ${VM}
virsh start ${VM}
unset EDITOR
12

Nope. It remains the same. :weary:
It keeps giving the same error.

— UPDATE —

I can connect with VNC (tightvnc/tigervnc) to port 5900 and it works fine.

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