I have the following code for port forwarding in mac os virtualization var ipAddr = in_addr() // 1. Convert String to in_addr inet_pton(AF_INET, guestIP, &ipAddr) let status = vmnet_network_configuration_add_port_forwarding_rule( config, UInt8(IPPROTO_TCP), // TCP protocol sa_family_t(AF_INET), // address family guestPort, // internal port (guest) externalPort, // external port (host) &ipAddr // internal address (guest IP) ) if status == .VMNET_SUCCESS { print("✅ Port Forwarding set: Mac:\(externalPort) -> VM(\(guestIP)):\(guestPort)") } else { print("❌ Port Forwarding failed for \(guestIP): \(status.rawValue)") } It is returning success but when i test it it does not work. Is there anything i am doing wrong? Please help me also in fixing this problem. Note: The app runs in sandbox i tried without sandboxing and it does not work either. Please refer to this link https://developer.apple.com/forums/thread/822025?login=true&page=1#884236022 how i am creating the VZVmnetNetworkDeviceAttachment

Hi everyone, I am developing a macOS virtualization manager (VirtualProg) using the Virtualization.framework. The application is distributed via the Mac App Store, so it operates strictly within the App Store Sandbox. I am looking for a reliable, programmatic way to discover the IP address assigned to a guest (both macOS and Linux). Is there a recommended "Sandbox-safe" API or pattern within the Virtualization framework—or a lower-level networking entitlement—that allows a host application to retrieve the guest's assigned IP address? Ideally, I am looking for a solution that does not require the user to manually install a non-sandboxed helper tool. Thanks in advance for any insights or guidance!

We are investigating bridged Wi-Fi DHCP behavior on recent macOS releases and would appreciate some clarification regarding the net.link.bridge.use_dhcp_xid sysctl. We observed that with the default setting, DHCP packets transmitted from a virtual machine through a bridged Wi-Fi interface may have their DHCP client identity modified (chaddr). In our testing, setting: net.link.bridge.use_dhcp_xid=0 prevents this behavior and restores the DHCP packet format observed on older macOS versions. We would like to better understand the intended purpose of this sysctl: What functionality does net.link.bridge.use_dhcp_xid control internally? Besides DHCP chaddr rewriting, what other bridge or DHCP processing behavior is affected by this setting? Is this sysctl related to DHCP snooping, anti-spoofing protection, Wi-Fi bridging compatibility, or another mechanism? Is the current default behavior (use_dhcp_xid=1) a recent change introduced in macOS 26.4.x? Is the modified DHCP behavior considered expected and supported, or is it intended as an implementation detail? For additional context, we previously submitted feedback regarding DHCP handling for virtual machines using Virtualization Framework. Since packet modification is restricted from user space, we are wondering whether this sysctl is related to DHCP processing implemented by the bridge subsystem to address DHCP spoofing, client identification, or Wi-Fi bridging limitations. One concern we have is that net.link.bridge.use_dhcp_xid appears to be a system-wide setting. In our use case, DHCP handling requirements may differ between virtual machines, networks, and environments. As a result, changing a global bridge behavior for the entire host system is not always desirable. If this sysctl is intended to control DHCP processing for bridged virtual machines, would it be possible to expose similar functionality on a per-interface, per-bridge, or per-VM basis rather than as a host-wide setting? This would allow virtualization products to adapt DHCP behavior to specific network environments without affecting all bridged networking on the host. One additional question: Apple suggested making this setting persistent via /etc/sysctl.conf. However, this file does not exist by default on our macOS 26.4.x systems. Is /etc/sysctl.conf still a supported mechanism for persistent sysctl configuration, or is there a preferred modern alternative? Any documentation or implementation details that can be shared would be greatly appreciated.

Hi guys, I am building a custom virtualization utility for macOS using the native Virtualization Framework. My goal is to allow local guest virtual machines to run in Bridged Mode (VZBridgedNetworkDeviceAttachment) so they can acquire their own distinct local IP address from my router and expose service ports directly to the local network. When attempting to compile and run my app with the com.apple.vm.networking entitlement, Xcode throws the following error:"Entitlement com.apple.vm.networking not found and could not be included in profile. This likely is not a valid entitlement and should be removed from your entitlements file" I understand that this is a restricted capability that is hidden from the standard Apple Developer Portal by default. I have already reached out via email to Apple Developer Support to request it, but I have not received a definitive answer on the process or exact entitlement string name. For those who have successfully shipped or tested a virtualization app with bridged networking, Is com.apple.vm.networking the correct string name for modern macOS versions, or is there a newer, specific identifier required? What is the actual entitlement that i should see in my developer account? I can't seem to find it in the docs as well. Would it be called "VM Networking" Thanks,

I'm pleased to share some significant updates that have recently been released for our Hypervisor and Virtualization frameworks. We've focused on enhancing efficiency, expanding capabilities, and addressing common developer needs. I believe these will be valuable for many of you. Here’s a look at what’s new: Hypervisor Updates We've introduced support for configuring the intermediate physical address (IPA) memory granularity of a VM. This allows for more granular memory mappings, enabling granularity sizes down to 4KB. This is particularly useful for certain specialized device drivers requiring finer memory control. Virtualization Framework Updates More Efficient VM Image Storage with ASIF: We've integrated support for the Apple Sparse Image Format (ASIF). This results in a smaller disk footprint and optimized transfer for VM disk images when using VZDiskImageStorageDeviceAttachment, improving storage efficiency. Custom Network Topologies with vmnet: We've added support for vmnet custom network topologies. This enables more flexible VM-to-VM communication based on logical networks with customized configurations, useful for complex testing or development environments. See VZVmnetNetworkDeviceAttachment to get started. Simplified VM Queue Discovery: It's now easier to discover a VM’s on-process thanks to a new property on VZVirtualMachine. This should aid in development and debugging when interacting directly with the VM's queue. These are some of the key highlights of the first beta, and I'm looking forward to seeing how these improvements will be utilized. I encourage you to explore the documentation for full details on these features.

I have a simple impossible task, to restore /var/root/Library/Application Support/multipassd/qemu/vault/instances/gcc-cobol/ubuntu-22.04-server-cloudimg-arm64.img as of 8:02 Saturday morning. Because /var/root is owned by, well, root, the usual techniques don't work. This is a VM image hosted by qemu via Canonical's Multipass. ISTM the strategy would be to first mount the NAS filesystem and then use tmutil(8) to list the backups and recover the file. But $ sudo mount -v -o rdonly -t smb //nasa.local/TimeMachine /usr/local/mnt/ mount: exec /Library/Filesystems/smb.fs/Contents/Resources/mount_smb for /usr/local/mnt: No such file or directory mount: /usr/local/mnt failed with 72 Must I defeat SIP to do this?