Network Mode: Bridged - No ipv4 connectivity

[clearxlate]

Greetings,

I have found a workaround to the issue (see below), but posting here to see if this is expected or if there is something specific to my configuration that is causing this behavior.

Note: Bridge works if I use en1 (wireless).

Version 4.4.5 (94)
MacOS: 14.4.1 (23E224)
2023 Mac mini - Apple M2 Pro
en0 - ethernet

When configuring a guest network to Network Mode: Bridged / Bridged Interface: en0, no ipv4 connectivity on ethernet. tcpdump on the guest ethernet interface does show ipv4 traffic from devices on my LAN (ARP/broadcast).

The bridge interface (bridge100) is created on the UTM host and the associated interfaces are added as members (Output provided below).

To get it working I issue:

ifconfig bridge100 macnat en0

So, I am able to make it work, but it requires manual intervention. Is there something I am missing?

Here is an example session on the host after the VM is started.

1. ifconfig of the bridge100 interface
2. "enabling" (?) MAC NAT
3. ifconfig of the bridge100 interface

% ifconfig bridge100
bridge100: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	options=3<RXCSUM,TXCSUM>
	ether 5e:e9:1e:6e:b2:64
	Configuration:
		id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
		maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
		root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
		ipfilter disabled flags 0x0
	member: en0 flags=3<LEARNING,DISCOVER>
	        ifmaxaddr 0 port 8 priority 0 path cost 0
	member: vmenet0 flags=3<LEARNING,DISCOVER>
	        ifmaxaddr 0 port 28 priority 0 path cost 0
	Address cache:
		aa:fa:b8:1e:76:b8 Vlan1 en0 1200 flags=0<>
		a2:7f:84:18:fb:f8 Vlan1 en0 1200 flags=0<>
		ac:24:11:30:4b:91 Vlan1 en0 1189 flags=0<>
		a0:a4:b7:f3:5f:de Vlan1 en0 1196 flags=0<>
		a6:3d:9:c5:25:cf Vlan1 en0 1200 flags=0<>
		ae:8c:38:9c:f1:36 Vlan1 en0 1200 flags=0<>
		ba:ef:c4:6b:b5:5d Vlan1 en0 1183 flags=0<>
		ac:e9:1e:e6:46:d6 Vlan1 en0 1200 flags=0<>
	nd6 options=201<PERFORMNUD,DAD>
	media: autoselect
	status: active
% sudo ifconfig bridge100 macnat en0
% ifconfig bridge100
bridge100: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	options=3<RXCSUM,TXCSUM>
	ether 5e:e9:1e:6e:b2:64
	Configuration:
		id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
		maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
		root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
		ipfilter disabled flags 0x0
	member: en0 flags=8003<LEARNING,DISCOVER,MACNAT>
	        ifmaxaddr 0 port 8 priority 0 path cost 0
	member: vmenet0 flags=3<LEARNING,DISCOVER>
	        ifmaxaddr 0 port 28 priority 0 path cost 0
	Address cache:
		a8:8c:b5:f9:a8:74 Vlan1 en0 1173 flags=0<>
		a8:d8:7e:f3:dd:4a Vlan1 en0 1171 flags=0<>
		ac:3e:53:20:ea:25 Vlan1 en0 1168 flags=0<>
		a0:5f:67:57:36:b7 Vlan1 en0 1159 flags=0<>
		a8:d0:83:c7:c3:61 Vlan1 en0 1153 flags=0<>
		aa:fa:b8:1e:76:b8 Vlan1 en0 1199 flags=0<>
		a6:3d:9:c5:25:cf Vlan1 en0 1198 flags=0<>
		ae:8c:38:9c:f1:36 Vlan1 vmenet0 1199 flags=0<>
		ba:ef:c4:6b:b5:5d Vlan1 en0 1194 flags=0<>
		ac:e9:1e:e6:46:d6 Vlan1 en0 1199 flags=0<>
	MAC NAT list:
		vmenet0 10.10.10.9 be:8c:38:9c:f1:36 1199
		en0 10.10.10.2 bc:e9:1a:a6:46:d6 1198
		en0 <snip> bc:e9:1e:e6:46:d6 1199
		en0 <snip> bc:e9:1e:e6:46:d6 1199
	nd6 options=201<PERFORMNUD,DAD>
	media: autoselect
	status: active
%

Thanks.

[kwankiu]

To get it working I issue:

ifconfig bridge100 macnat en0

Same issue here

UTM 4.5.3 (99)
macOS 15.3.1
Macbook Pro M1 2020
en0 - WiFi

Have to workaround this by

sudo ifconfig bridge100 addm en0
sudo ifconfig bridge100 macnat en0