ARP failed at the Macbook host side, and thus ping failed.

[ppel33]

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Describe the issue
Replace this text with a clear and concise description of what the issue is.

ARP failed.
Created a vm via UTM, ping from my macbook to the VM failed, which was due to ARP failing to get the MAC address for the VM IP.

Configuration

• UTM Version: 4.6.5(108)
• macOS Version: Sequoia 15.0
• Mac Chip (Intel, M1, ...): Intel, 8 core Intel Core i9

Crash log
If the app crashed, you need a crash log. To get your crash log, open Console.app, go to Crash Reports, and find the latest entry for either UTM, QEMU, QEMUHelper, or qemu-*. Right click and choose Reveal in Finder. Attach the report here.

no crash.

Debug log
For all issues related to running a VM, including crashes, you should attach a debug log. (This is unavailable for macOS-on-macOS VMs. Attach an excerpt of your system log instead.)
To get the Debug log: open UTM, and open the settings for the VM you wish to launch. Near the top of the QEMU page is Debug Log. Turn it on and save the VM. After you experience the issue, open the VM settings again and select Export Log... and attach it here.

% ping 192.168.0.203
PING 192.168.0.203 (192.168.0.203): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2
^C
--- 192.168.0.203 ping statistics ---
4 packets transmitted, 0 packets received, 100.0% packet loss

As you can see, the entry for 192.168.0.203 is incomplete, thus ping 192.168.0.203 failed.
% arp -a
? (192.168.0.1) at 3c:6a:d2:97:f5:dc on en0 ifscope [ethernet]
? (192.168.0.78) at d6:89:a8:2e:d4:64 on en0 ifscope [ethernet]
? (192.168.0.165) at de:7:5d:e3:b6:cb on en0 ifscope [ethernet]
? (192.168.0.203) at (incomplete) on en0 ifscope [ethernet]
? (192.168.0.207) at 80:2b:f9:4a:18:35 on en0 ifscope [ethernet]
? (192.168.0.236) at f8:ff:c2:49:87:d2 on en0 ifscope [ethernet]
mdns.mcast.net (224.0.0.251) at 1:0:5e:0:0:fb on en0 ifscope permanent [ethernet]

However if I issue a ping from the vm to my macbook host, the arp cache for 192.168.0.203 will be populated correctly on my macbook.

Upload VM
If your issue is related to a specific VM, please upload the config.plist from your VM's .utm directory. To get this, right-click the VM in UTM and choose "Show in Finder". Then right-click the selected file in Finder and choose "Show Package Contents". The config.plist file is now visible. Right-click it and choose "Compress". Attach the resulting config.plist.zip file here.
You can upload the entire .utm if needed, but note this includes your VM's drive image and may contain personal data. Since Github has an attachment size limit, you may want to upload to another service such as Google Drive. Link it here.
Not sure if it's related to VM. Here's the config.plist though

Backend Apple ConfigurationVersion 4 Display DynamicResolution HeightPixels 1024 PixelsPerInch 80 WidthPixels 1280 Drive Identifier EFA81099-E426-421B-B94B-56D0192AEAA7 Nvme ReadOnly Identifier 67F8799F-4263-4DD3-A994-1B7764B69FED ImageName 67F8799F-4263-4DD3-A994-1B7764B69FED.img Nvme ReadOnly Information Icon linux IconCustom Name u2 UUID 1E0787C1-0BBB-4713-9636-A2BDFA0EF24A Network MacAddress 7e:16:b0:2c:1f:51 Mode Bridged Serial System Architecture x86_64 Boot EfiVariableStoragePath efi_vars.fd OperatingSystem Linux UEFIBoot CPUCount 4 GenericPlatform machineIdentifier YnBsaXN0MDDRAQJUVVVJRE8QEH4HYugn10FGpX5ZFNiUdAcICxAA AAAAAAABAQAAAAAAAAADAAAAAAAAAAAAAAAAAAAAIw== MemorySize 8192 Virtualization Audio Balloon ClipboardSharing Entropy Keyboard Generic Pointer Mouse Rosetta

[ppel33]

config.plist.zip

here's the config.plist.zip