Kvm network troubleshooting



  • @atahaynah

    cockpit works on port 9090, and editing port on the VM should not change cockpit web interface, cause VMs takes another IP than the hypervisor KVM machine. check cockpit service

    systemctl status cockpit
    systemctl status cockpit.socket



  • @Pete-S this is all which i could provide as I couldn’t remotely connect to the server



  • Your server has an IP address of 192.168.122.1? Is that correct? Nothing wrong with that technically, but it would be exceptionally unusual. That's almost always the gateway address. What is the address of your gateway?



  • Let's check out the listening ports. What is the output of...

    netstat -tulpn


  • How are you trying to connect? Cockpit only? Have you tried SSH?



  • @scottalanmiller

    This is actually a very funny situation. This person is the guy that is preceding me in my old work.

    He never got personal hand over from me (he got hired 2-3 months after i left, so only documented handover), and they hired Windows specialist and I deploy mostly Linux stuff, so god be with him.

    I told him to ask his management since we are in the same town for official hand over but he is trying to learn via practice in production environment.

    I had my reasons to deploy KVM, and sadly its not very familiar for him, so expect alot of posts/topics.

    It is funny how he find Mangolassi and became member here, I guess we are the only 2 Jordanians in ML.

    Regardless please man try to setup centos KVM in home lab (it is alot easier than you think, and check topics here about it), and get the basics covered and dont change stuff in Prod, the first issue you posted is cause of that, so learn it at home or replace it, it hosts 5-6 VMs. We are here to help ofcourse, but changing stuff in production and causing time out will get you in trouble with management.

    Guys can KVM qcow2 images be converted in something Windows HyperV can use ?



  • This post is deleted!


  • @Emad-R said in Kvm network troubleshooting:

    @scottalanmiller said in Kvm network troubleshooting:
    Your server has an IP address of 192.168.122.1? Is that correct? Nothing wrong with that technically, but it would be exceptionally unusual. That's almost always the gateway address. What is the address of your gateway?

    Thats fine Scott, its NAT network creating for internal Networks by KVM by default, so i dont think its issue. Its IP you get from that pool if you choose NAT instead of bridge in network VM settings.

    What we need to know is the history of commands being run, and why they are being run? what is the purpose of all this or goal.

    That said shutdown all VMs, find command to do that and reboot the server, hopefully that might bring SSH up and cockpit.



  • What happens if you ping 192.168.1.40 ?

    Why enp4s0 is not getting that IP ?

    Did you give VM that IP ?

    The centos KVM machine should have that IP = 192.168.1.40

    That IP should be reserved in the FG firewall, how did you replace it ? and why ?



  • @Emad-R

    (Guys can KVM qcow2 images be converted in something Windows HyperV can use ?)
    after i resolve the issue this will be my next topic to search about



  • @Emad-R @scottalanmiller

    long story short

    i created a domain controller , so i wanted to bridge the connection of this Virtual machine and thats what happened .

    no configuration have been done to the configuration files its all done from the GUI

    i am confident that as you said in tailed replies , a virtual machine grabbed the address but now i am unable to revert it back .

    which interface i should reconfigure to get back the connection ?



  • @atahaynah

    ok DC and bridge I am not sure about the terminology or bridging , since all other IPs in that location is using the same subnet, you also have EMR on the same network.
    Also you dont want to interfere with the firewall, since as far as i know DC requires DHCP (not sure). And we are currently using DHCP from firewall.

    Regarding GUI changes, let me assure you with cockpit you can manage the whole system and do alot of changes from the GUI, changes that you can never revert back.

    Regarding my replies I said what happens if you ping that IP ? does it reply back ?

    If it replies back that means the IP is taken/IP conflict, if not that means something else



  • @scottalanmiller said in Kvm network troubleshooting:

    Your server has an IP address of 192.168.122.1? Is that correct? Nothing wrong with that technically, but it would be exceptionally unusual. That's almost always the gateway address. What is the address of your gateway?

    That's libvirts virtual bridge address for the NAT network.



  • So looking at the interfaces it looks like enp4s0 was set up with an address. All of the VMs are macvtap interfaces on top of that nic for network access. Then libvirt created a virtual bridge for the default NAT network. If that's correct then you don't need to create a bridge or anything. Just tell the VM to use enp4s0 for networking and macvtap will auto set up the tun/tap device for access. You have no address on enp4s0 which is why I'm guessing you cant access the host.

    If you can get into the VMs, you should be able to SSH to the virtual bridge (which is the host) if they have an interface on the NAT network.



  • @stacksofplates said in Kvm network troubleshooting:

    @scottalanmiller said in Kvm network troubleshooting:

    Your server has an IP address of 192.168.122.1? Is that correct? Nothing wrong with that technically, but it would be exceptionally unusual. That's almost always the gateway address. What is the address of your gateway?

    That's libvirts virtual bridge address for the NAT network.

    Oh, duh, I missed the bridge. Carry on. 🙂