There are two main ways to set up networking on OS X / macOS, as it does not function with what QEMU defaults to for network settings: ----------------------------------- User Mode Networking (Easier Setup) ----------------------------------- By default, QEMU uses user mode networking (SLiRP). This networking mode is the slowest and is not visible via the outside network, but requires no host-side setup, so it's perfect if you just want internet but don't care about latency or about connecting to the VM from an external source. In order to do this, change the line in your qemu-system-x86_64 command (found in boot-macOS.sh) to the following: -netdev user,id=net0 -device network_adapter,netdev=net0,id=net0,mac=52:54:00:c9:18:27 \ Once you set network_adapter to the preferred adapter, no further setup is required; your internet should Just Werk™ in your virtual machine! For further information on detailed configuration options, see QEMU's documentation on networking ( http://wiki.qemu.org/Documentation/Networking ) Here is the list of network adapters supported by macOS, e1000-82545em - The problem that we run into here is that OS X is nitpicky about what emulated networking devices it is willing to accept. The e1000-82545em is a known adapter that can be used on pretty much any version of MacOS. To use this adapter, replace network_adapter with e1000-82545em vmxnet3,virtio-net-pci - An alternative solution to e1000. Instead of emulating the e1000, these are paravirtualized NICs, which can allow for better performance (in theory). The only catch is that the you need to have a recent version of MacOS (10.11 or later). To use these adapters, replace network_adapter with vmxnet3 or virtio-net-pci. SSH access in user mode ----------------------- Although the IP address of the VM is not visible to the outside, it is possible to use port forwarding to access the VM's ports from your host, eg the SSH port. To achieve that: - In MacOS, turn on SSH under System Preferences > Sharing > Remote Login. - Modify the startup script to include `-netdev user,id=net0,hostfwd=tcp::10022-:22` - Use `ssh localhost -p10022` to get in. You can use the same for VNC. ----------------------------------- Tap Networking (Better Performance) ----------------------------------- Installing "virt-manager" automagically creates the "virbr0" local private bridge :-) sudo apt-get install uml-utilities virt-manager sudo ip tuntap add dev tap0 mode tap sudo ip link set tap0 up promisc on sudo brctl addif virbr0 tap0 sudo ip link set dev virbr0 up # as needed sudo ip link set dev tap0 master virbr0 Note: If `virbr0` network interface is not present on your system, it may have been deactivated. Try enabling it by using the following commands, virsh net-start default virsh net-autostart default Add "-netdev tap,id=net0,ifname=tap0,script=no,downscript=no -device e1000-82545em,netdev=net0,id=net0,mac=52:54:00:c9:18:27 \" to your qemu-system-x86_64 command. Using an rc.local startup script -------------------------------- I have the following commands present in `/etc/rc.local`. #!/usr/bin/env bash sudo ip tuntap add dev tap0 mode tap sudo ip link set tap0 up promisc on sudo ip link set dev virbr0 up sudo ip link set dev tap0 master virbr0 This has been enough for me so far. Note: You may need to enable the `rc.local` functionality manually on modern Ubuntu versions. Check out the [notes](notes.md) included in this repository for details. QEMU networking tip ------------------- # printf '52:54:00:AB:%02X:%02X\n' $((RANDOM%256)) $((RANDOM%256)) # generates QEMU compatible mac addresses! ------------------ Bridged Networking ------------------ QEMU defaults to using NAT for its guests. It has a built-in DHCP server that provides addresses from the 192.168.12x.0 subnet. However, this configuration makes file sharing, printer sharing, and other common networking activities harder to use in a home network. Bridged networking allows your QEMU guest to get an address on the same subnet as the host computer. For example, many home networks let the wireless router handle IP assignment via DHCP. Here are the steps for setting up the bridge. To setup bridged networking from the command line, refer to this documentation at the Ubuntu website. https://help.ubuntu.com/community/KVM/Networking Ultimately, the script for booting the QEMU guest will need a line similar to the following to enable bridged networking in the guest: -netdev bridge,id=net0,br=virbr0,"helper=/usr/lib/qemu/qemu-bridge-helper" On some systems the `qemu-bridge-helper` file has incorrect permissions. For it to work, it needs to be setuid root. This can be accomplished with this command: $ sudo chmod u+s /usr/lib/qemu/qemu-bridge-helper Note that this is sometimes viewed as a security hole. Be careful and understand what you are doing before running this command. ----------------------- Bridged Networking 2023 ----------------------- sudo mkdir -p /etc/qemu sudo cp bridge.conf /etc/qemu sudo chmod u+s /usr/lib/qemu/qemu-bridge-helper sudo ip link add name br0 type bridge sudo ip link set dev br0 up sudo ip link set enx00e04c680a67 master br0 && sudo dhclient br0 $ brctl show bridge name bridge id STP enabled interfaces br0 8000.ead0ee60b7c1 yes enx00e04c680a67 tap0 Use the following network device in scripts: -netdev bridge,id=net0,br=br0,"helper=/usr/lib/qemu/qemu-bridge-helper" -device virtio-net-pci,netdev=net0,id=net0,mac=00:16:CB:00:11:34 Also see https://dortania.github.io/OpenCore-Post-Install/universal/iservices.html to tweak the config.plist file.