try to load af_packet module before up

image/overlay/etc/network/interfaces

@@ -3,4 +3,5 @@ iface lo inet loopback
 
 auto eth0
 iface eth0 inet dhcp
+	 pre-up modprobe af_packet
     post-up ip route del default || true; ip route add default via GATEWAY_ADDRESS

test.sh

@@ -8,5 +8,5 @@ set -euo pipefail
   --cmdline "modules=ext4 root=/dev/vda rootfstype=ext4 rw console=hvc0" \
   --cpus boot=${CPU_COUNT:-4} \
   --memory size=${MEMORY:-4G},shared=on \
-  --net "tap=,ip=,mac=,mask="
+  --net "tap="
   $@