diff --git a/debian/wit-network-config.postinst b/debian/wit-network-config.postinst
index 2ad5aaa..5e0a2fa 100755
--- a/debian/wit-network-config.postinst
+++ b/debian/wit-network-config.postinst
@@ -36,8 +36,11 @@ case "$1" in
 	    exit 2
         fi
 
-
-        MGMT_MAC=$(ip -br link show dev $(ip -4 -br addr | grep 10.0. | awk '{ print $1 }') | awk '{ print $3 }')
+        declare -A MACS
+        for if in mgmt feth1 feth2 up1 up2
+          do
+            MACS["$if"]=$(dig txt +short mac.$if.$HOSTNAME)    ## careful mac will be wrapped in quotes, but we don't care since we'll need it again wrapped in quotes (so far)
+        done
 
      ## END variables
 
@@ -104,15 +107,12 @@ case "$1" in
 
 
       # write udev rules for device names
-        echo 'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="'$MGMT_MAC'", ATTR{type}=="1", NAME="mgmt1"' >/etc/udev/rules.d/70-persistent-net.rules
-        i=0
-        for nic in $(ip -br link | awk '{ print $1 }'); do
-            if ethtool $nic | grep -q 10000; then
-                i=$((i+1))
-                echo 'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="'$(cat /sys/class/net/$nic/address)'", ATTR{type}=="1", NAME="feth'$i'"' >>/etc/udev/rules.d/70-persistent-net.rules
-            fi
-        done
-        sed -i "/$MGMT_MAC.*feth./d" /etc/udev/rules.d/70-persistent-net.rules
+        for if in ${!MACS[@]}
+          do
+            ifmac=${MACS[$if]}
+            [ "$if" == "mgmt" ] && if=mgmt1
+            [ -z "$ifmac" ] || echo 'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=='$mac', ATTR{type}=="1", NAME="'${if}'"'
+        done >/etc/udev/rules.d/70-persistent-net.rules