Hi, I've seen this before. First, the simple steps: have you started that network? (virsh start network-name) do you have installed the tools to work with bridges in your OS? can you check if the bridge exist in your OS and if the vm's interface is attached to it? In rhel you use the command brctl to do that, don't know about ubuntu... Best Regards, DR On Thu, Apr 16, 2020 at 7:32 PM Computers Issues < computerslover123(a)gmail.com&gt; wrote: > Hello there, > > I wanted to share a problem I'm having with libvirt, for the case someone > here could know how to solve it. > > I'm using an Ubuntu 18.04 LTS, I have libvirtd already installed and I > think I got all the dependencies installed. So, I'm using virsh net-create > to create this network: > > <network> > <name>pepito</name> > <forward mode='nat'/> > <bridge name='virbr2' stp='on' delay='0'/> > <ip address='192.168.150.1' netmask='255.255.255.0'> > <dhcp> > <range start='192.168.150.2' end='192.168.150.254'/> > </dhcp> > </ip> > </network> > > And then I create a domain with this xml: > > <domain type='qemu' xmlns:qemu=' > http://libvirt.org/schemas/domain/qemu/1.0'> > <name>ARM</name> > <memory unit='KiB'>262144</memory> > <currentMemory unit='KiB'>262144</currentMemory> > <os> > <type arch='armv7l' machine='virt-2.9'>hvm</type> > <kernel>~/zImage</kernel> > <cmdline>console=ttyAMA0 root=/dev/vda</cmdline> > <boot dev='hd'/> > </os> > > <on_poweroff>destroy</on_poweroff> > <on_reboot>restart</on_reboot> > <on_crash>destroy</on_crash> > <devices> > <emulator>/usr/bin/qemu-system-aarch64</emulator> > <disk type='file' device='disk'> > <driver name='qemu' type='qcow2'/> > <source file=' ~/rootfs.qcow2'/> > <target dev='hda' bus='virtio'/> > </disk> > <controller type='virtio-serial' index='0'> > <address type='virtio-mmio'/> > </controller> > <interface type='network'> > <mac address='52:54:00:09:a4:37'/> > <model type='virtio'/> > <source network='pepito'/> > <address type='virtio-mmio'/> > </interface> > </devices> > <qemu:commandline> > <qemu:arg value='-device'/> > <qemu:arg value='virtio-net-pci'/> > <qemu:arg value='-netdev'/> > <qemu:arg value='user,id=net1'/> > </qemu:commandline> > </domain> > > They both work as I created them in a different computer and everything > works. But I'm trying it on my other Ubuntu machine, and once virsh creates > the network and the domain, my VM never get an IP from that DHCP range. > This is libvirtd log: > > abr 17 00:48:11 usuario-System-Product-Name dnsmasq-dhcp[13741]: DHCP, IP > range 192.168.150.2 -- 192.168.150.254, lease time 1h > abr 17 00:48:11 usuario-System-Product-Name dnsmasq-dhcp[13741]: DHCP, > sockets bound exclusively to interface virbr2 > abr 17 00:48:11 usuario-System-Product-Name dnsmasq[13741]: reading > /etc/resolv.conf > abr 17 00:48:11 usuario-System-Product-Name dnsmasq[13741]: using > nameserver 127.0.0.53#53 > abr 17 00:48:11 usuario-System-Product-Name dnsmasq[13741]: read > /etc/hosts - 7 addresses > abr 17 00:48:11 usuario-System-Product-Name dnsmasq[13741]: read > /var/lib/libvirt/dnsmasq/pepito.addnhosts - 0 addresses > abr 17 00:48:11 usuario-System-Product-Name dnsmasq-dhcp[13741]: read > /var/lib/libvirt/dnsmasq/pepito.hostsfile > > > Does anybody know why it could be that the VM never gets an IP from the > range I defined? As I said, exactly the same configuration worked in a > different machine, I don't know why it does not work here. > > Thank you so much!! > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&... Libre > de virus. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&... > <#m_1529389328306967443_m_-9208904238504833900_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >

On 4/17/20 1:31 AM, Computers Issues wrote: > Hello there, > There is nothing obviously wrong with XMLs. Couple of things to try: 1) are you sure that the guest actually ask for an IP address? What happens when you 'dhclient eth0' from inside the guest (or whatever the equivalent is)? 2) is dnsmasq running on the host? If so, there should be /var/lib/libvirt/dnsmasq/pepito.conf file, can you share its content? 3) Firewall. A lot of times when something network related doesn't work I shut the firewall down and retry. It helps me rule one possible source out. Michal

On 4/17/20 12:44 PM, Computers Issues wrote: > Hello! > > Thanks for your answer. > > Well, I think it has to ask for an IP as I have the same configuration > in a different machine (with the same OS) and it works, there I see the > DHCP packets and so on, but not here. Well, do you actually see DHCP traffic on the virbr2 bridge? Because if not then the guest configuration is probably not correct. > And yeah, that pepito.conf file > exists, this is its content: > ##WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE > ##OVERWRITTEN AND LOST. Changes to this configuration should be made using: > ## virsh net-edit pepito > ## or other application using the libvirt API. > ## > ## dnsmasq conf file created by libvirt > strict-order > user=libvirt-dnsmasq > pid-file=/var/run/libvirt/network/pepito.pid > except-interface=lo > bind-dynamic > interface=virbr2 > dhcp-range=192.168.150.2,192.168.150.254 > dhcp-no-override > dhcp-authoritative > dhcp-lease-max=253 > dhcp-hostsfile=/var/lib/libvirt/dnsmasq/pepito.hostsfile > addn-hosts=/var/lib/libvirt/dnsmasq/pepito.addnhosts This looks good. I suspect it is the guest not asking for DHCP. If it did, this configuration would assign an IP address. Michal

Hi, That was right. I mean, I've tried it at the same time in both machines I have (the one where it works and the other), and using tcpdump -i virbr2 in both ones, after creating the domain with virsh, showed that the right one is getting DHCP traffic, but there's no DHCP request or anything about DHCP in the one that is not working.