如何告訴 qemu 在網橋上使用特定的 MAC 地址？

當我使用創建 VM時，VM通過生成以下 XML 配置自動virt-install連接到網路介面：virbr0

<interface type="network">
 <source network="default"/>
 <mac address="52:54:00:6a:40:f8"/>
 <model type="e1000e"/>
</interface>

現在我正在嘗試複製它。

檢查預設的 libvirt 網路配置/var/lib/libvirt/dnsmasq/default.conf，我知道網路介面名稱是virbr0.

我設法告訴 qemu 使用相同的界面，如下所示： qemu-system-x86_64 -net nic -net bridge,br=virbr0" ...

但我不知道如何像在 XML 配置中那樣指定自定義 MAC 地址。有人可以啟發我嗎？

對於水龍頭設備，您似乎可以像這樣設置 MAC 地址

-netdev type=tap,id=net0,ifname=tap0,script=tap_ifup,downscript=tap_ifdown,vhost=on \
-device virtio-net-pci,netdev=net0,addr=19.0,mac=52:54:00:6a:40:f8

但這不是我想要的。我只想使用那座virbr0橋。

我終於想通了！

所以這是virt-install預設情況下會執行的操作：

sudo virt-install --network network=default,model=e1000,mac=00:11:22:33:44:55

等價於qemu-system-x86_64：

INTERFACE_NAME="$(sudo cat /var/lib/libvirt/dnsmasq/default.conf | grep "^interface=" | cut -d'=' -f2-)"
sudo qemu-system-x86_64 -net nic,model=e1000,macaddr=00:11:22:33:44:55 -net bridge,br=${INTERFACE_NAME}

我建議先確保default網路處於活動狀態：

if ! sudo virsh net-list | grep default | grep --quiet active; then
   sudo virsh net-start default
fi

注意：整個預設網路事物由軟體包提供libvirt-daemon-config-network（至少在 Fedora 上）。

從 qemu 手冊頁：

  -net nic[,netdev=nd][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]
         Legacy  option to configure or create an on-board (or machine default) Network Interface Card(NIC) and connect it either to the emulated hub with ID 0 (i.e. the default hub), or to the netdev nd.  If model is omitted,
         then the default NIC model associated with the machine type is used. Note that the default NIC model may change in future QEMU releases, so it is highly recommended to always specify a model. Optionally, the  MAC  ad‐
         dress  can  be changed to mac, the device address set to addr (PCI cards only), and a name can be assigned for use in monitor commands. Optionally, for PCI cards, you can specify the number v of MSI-X vectors that the
         card should have; this option currently only affects virtio cards; set v = 0 to disable MSI-X. If no -net option is specified, a single NIC is created. QEMU can emulate several different models of network  card.   Use
         -net nic,model=help for a list of available devices for your target.

  -net user|tap|bridge|socket|l2tpv3|vde[,...][,name=name]
         Configure a host network backend (with the options corresponding to the same -netdev option) and connect it to the emulated hub 0 (the default hub). Use name to specify the name of the hub port.

從 virt-install 手冊頁：

NETWORKING OPTIONS
  -w, --network
      Syntax: -w, --network OPTIONS

      Connect the guest to the host network. Examples for specifying the network type:

      bridge=BRIDGE
             Connect to a bridge device in the host called BRIDGE. Use this option if the host has static networking config & the guest requires full outbound and inbound connectivity  to/from the LAN. Also use this if live migra‐
             tion will be used with this guest.

      network=NAME
             Connect  to  a virtual network in the host called NAME. Virtual networks can be listed, created, deleted using the virsh command line tool. In an unmodified install of libvirt there is usually a virtual network with a
             name of default. Use a virtual network if the host has dynamic networking (eg NetworkManager), or using wireless. The guest will be NATed to the LAN by whichever connection is active.

      type=direct,source=IFACE[,source.mode=MODE]
             Direct connect to host interface IFACE using macvtap.

      user   Connect to the LAN using SLIRP. Only use this if running a QEMU guest as an unprivileged user. This provides a very limited form of NAT.

      none   Tell virt-install not to add any default network interface.

      If --network is omitted a single NIC will be created in the guest. If there is a bridge device in the host with a physical interface attached, that will be used for connectivity. Failing that, the virtual network called  de‐
      fault will be used. This option can be specified multiple times to setup more than one NIC.

      Some example suboptions:

      model.type or model
             Network device model as seen by the guest. Value can be any nic model supported by the hypervisor, e.g.: 'e1000', 'rtl8139', 'virtio', ...

      mac.address or mac
             Fixed  MAC address for the guest; If this parameter is omitted, or the value RANDOM is specified a suitable address will be randomly generated. For Xen virtual machines it is required that the first 3 pairs in the MAC
             address be the sequence '00:16:3e', while for QEMU or KVM virtual machines it must be '52:54:00'.

      filterref.filter
             Controlling firewall and network filtering in libvirt. Value can be any nwfilter defined by the virsh 'nwfilter' subcommands. Available filters can be listed by running 'virsh  nwfilter-list',  e.g.:  'clean-traffic',
             'no-mac-spoofing', ...

      virtualport.* options
             Configure the device virtual port profile. This is used for 802.Qbg, 802.Qbh, midonet, and openvswitch config.

             Use --network=? to see a list of all available sub options.  Complete details at https://libvirt.org/formatdomain.html#elementsNICS

             This option deprecates -m/--mac, -b/--bridge, and --nonetworks

引用自：https://unix.stackexchange.com/questions/665665