diff --git a/init/functions b/init/functions
index 19a522e..4f099dd 100644
--- a/init/functions
+++ b/init/functions
@@ -128,6 +128,21 @@ umount_retry() {
     return 0
 }
 
+get_iface_from_mac() {
+    local mac="$1"
+    local iface
+    iface="$(ip -o link | grep -i "$mac" | awk '{print $2}' | cut -d ':' -f1)"
+    echo "$iface"
+}
+
+get_qubes_managed_iface() {
+    local mac
+    local qubes_iface
+    mac="$(qubesdb-read /qubes-mac)"
+    qubes_iface="$(get_iface_from_mac "$mac")"
+    echo "$qubes_iface"
+}
+
 initialize_home() {
     local home_root
     local mode
diff --git a/network/network-manager-prepare-conf-dir b/network/network-manager-prepare-conf-dir
index 7eb09c1..e76ce01 100755
--- a/network/network-manager-prepare-conf-dir
+++ b/network/network-manager-prepare-conf-dir
@@ -1,5 +1,9 @@
 #!/bin/sh
 
+# Source Qubes library.
+# shellcheck source=init/functions
+. /usr/lib/qubes/init/functions
+
 NM_CONFIG_DIR=/etc/NetworkManager/system-connections
 if [ -d $NM_CONFIG_DIR ] && [ ! -h $NM_CONFIG_DIR ]; then
     mkdir -p /rw/config/NM-system-connections
@@ -20,7 +24,7 @@ sed -r -i -e "s/^#?plugins=.*/plugins=keyfile/" /etc/NetworkManager/NetworkManag
 # starting NetworkManager, otherwise it will try default DHCP configuration
 # first and only after a timeout fallback to static one - introducing delay in
 # network connectivity
-export INTERFACE=eth0
+export INTERFACE="$(get_qubes_managed_iface)"
 if qubesdb-read /qubes-ip >/dev/null 2>/dev/null &&
         [ -e /sys/class/net/$INTERFACE ] &&
         [ ! -r /etc/NetworkManager/system-connections/qubes-uplink-$INTERFACE ]; then
diff --git a/vm-init.d/qubes-firewall b/vm-init.d/qubes-firewall
index 483debc..1db1c72 100755
--- a/vm-init.d/qubes-firewall
+++ b/vm-init.d/qubes-firewall
@@ -19,7 +19,7 @@ start()
 
     if qsvc qubes-firewall ; then
         echo -n $"Starting Qubes Firewall monitor:"
-        /sbin/ethtool -K eth0 sg off
+        /sbin/ethtool -K "$(get_qubes_managed_iface)" sg off
         /usr/sbin/qubes-firewall &
         success
         echo ""
diff --git a/vm-systemd/misc-post.sh b/vm-systemd/misc-post.sh
index 031e8a7..0533013 100755
--- a/vm-systemd/misc-post.sh
+++ b/vm-systemd/misc-post.sh
@@ -15,7 +15,10 @@ fi
 # DispVM (to override DispVM-template IP) and in case when qubes-ip was
 # called by udev before loading evtchn kernel module - in which case
 # qubesdb-read fails
-INTERFACE=eth0 /usr/lib/qubes/setup-ip
+QUBES_MANAGED_IFACE="$(get_qubes_managed_iface)"
+if [ "x$QUBES_MANAGED_IFACE" != "x" ]; then
+INTERFACE="$QUBES_MANAGED_IFACE" /usr/lib/qubes/setup-ip
+fi
 
 if [ -x /rw/config/rc.local ] ; then
     /rw/config/rc.local
diff --git a/vm-systemd/network-proxy-setup.sh b/vm-systemd/network-proxy-setup.sh
index ec8504e..418db31 100755
--- a/vm-systemd/network-proxy-setup.sh
+++ b/vm-systemd/network-proxy-setup.sh
@@ -1,5 +1,9 @@
 #!/bin/sh
 
+# Source Qubes library.
+# shellcheck source=init/functions
+. /usr/lib/qubes/init/functions
+
 # Setup gateway for all the VMs this netVM is serviceing...
 network=$(qubesdb-read /qubes-netvm-network 2>/dev/null)
 if [ "x$network" != "x" ]; then
@@ -24,5 +28,5 @@ if [ "x$network" != "x" ]; then
     if [ -n "$gateway6" ]; then
         echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
     fi
-    /sbin/ethtool -K eth0 sg off || true
+    /sbin/ethtool -K "$(get_qubes_managed_iface)" sg off || true
 fi