Am 21.01.2018 um 10:53 schrieb Binarus: > On 20.01.2018 17:04, Hermann Himmelbauer wrote: >> Hi, >> I today upgraded my KVM host from Debian 8 to the latest Debian 9 >> (Stretch). This worked perfectly, however, 2 old guest systems (SuSE >> 9.1, kernel 2.6.7 / 2.6.5) have no network access. >> >> All other machines running on this host are Linux Debian machines and >> use the "virtio" networking drivere whereas those two old machines use >> RTL8139 (or e1000, makes no difference). >> >> On the guest side, the networking interface (eth0 / rtl8139) is up, it >> states "Link Up / 100MBit" in the log file, everything looks fine, but I >> can't get out, no ping, empty arp table etc. >> >> Basically, I use bridging for the virtual hosts, this looks like this: >> >> br0 8000.0026186273f4 no eth0 >> vnet0 >> vnet1 >> >> or like so: >> >> port no mac addr is local? ageing timer >> 1 00:00:24:cc:c7:85 no 0.42 >> 1 00:19:66:b3:cb:34 no 3.97 >> 1 00:22:b0:cf:04:b2 no 0.03 >> >> >> What is interesting is that I cannot find the MAC Address of the 2 >> machines in the above table, which is probably not good. > > I had a similar problem some years ago. In my case, the network in the > guests generally worked, but was stuttering such extremely that it > actually could not be used. > > After some research, it turned out that I had to assign a MAC address to > the guests' (virtual) NICs explicitly. > > You haven't told us how you configure / start your VMs. I personally > don't use libvirt and colleagues, but I am starting the VMs from the > command line. Consequently, I don't know how to assign MAC addresses > using the high-level configuration tools. What I am doing on the command > line (as far as it concerns the network) is something like that (please > imagine the following code to be on one line): > > /usr/bin/qemu-system-x86_64 > [...] > -device virtio-net-pci,vlan=0,mac=02:01:01:01:02:01 > -net > tap,vlan=0,name=dax,ifname=dax0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown > [...] > > Please note how the MAC address is explicitly assigned. script and > downscript are just two simple wrappers which add the virtual NIC to an > existing bridge which connects them with the host and the other VMs. > > The disadvantage of this method is that you have to manage the MAC > addresses yourself (you ultimately must make sure that every VM gets its > own and that no other device in the world (in practice in most cases: in > your network) has the same as one of your virtual NICs). The MAC address > shown above is from the semi-official private MAC address space, so I am > hopefully out of trouble in this respect. > > Please let us know if this solves your problem. Thank you for your quick reply, I did not (yet) solve the problem, but I unfortunately don't fully understand this "tap" device. I start my virtual machines via libvirt (virt-manage / virsh). However, looking at the command line, the virtual machine is started like this: qemu-system-x86_64 -enable-kvm -name guest=horn,debug-threads=on -S -object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-11-horn/master-key.aes -machine pc-1.1,accel=kvm,usb=off,dump-guest-core=off -cpu qemu32 -m 1024 -realtime mlock=off -smp 2,sockets=2,cores=1,threads=1 -uuid af3996ca-e192-65f0-4318-bd5054311d42 -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-11-horn/monitor.sock,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -boot strict=on -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/dev/gaia_data1/horn,format=raw,if=none,id=drive-ide0-0-0 -device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -netdev tap,fd=34,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=52:54:00:9a:db:c6,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -vnc 127.0.0.1:0 -device cirrus-vga,id=video0,bus=pci.0,addr=0x2 -device intel-hda,id=sound0,bus=pci.0,addr=0x4 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5 -msg timestamp=on So, the MAC-Address is assigend fixed. However, doing a "ip tuntap" shows the following: vnet8: tap vnet6: tap vnet_hdr vnet4: tap vnet_hdr vnet2: tap vnet0: tap vnet_hdr vnet9: tap vnet_hdr vnet7: tap vnet_hdr vnet5: tap vnet_hdr vnet3: tap vnet_hdr vnet1: tap vnet_hdr vnet2 / vnet8 are exactly the machines that have no network access. So, I wonder if my problem has something to do with VLANs? I read somewhere that only virtio support VLANs, the rtl8139 does not. I do not use VLANs in any way, but perhaps there's something misconfigured? What I do not know is how these "vnetX" - devices are created - you mentioned two scripts - what do they do? Are the MAC addresses somehow assigned to the "ventX" - devices, and if yes, how? Best Regards, Hermann -- hermann@xxxxxxx PGP/GPG: 299893C7 (on keyservers)
