Update subnet-down.tmpl

tinc/subnet-down.tmpl

@@ -1,2 +1,17 @@
 #!/bin/ash
 echo "Route down: \$SUBNET weight \$WEIGHT via \$NODE (\$REMOTEADDRESS:\$REMOTEPORT)"
+nonMACChars=`echo \$SUBNET | tr -d "[:digit:]" | tr -d [:ABCDEFabcdef]`
+macFile="/tmp/tinc_peer_mac_\$NODE"
+if [ -z "\$nonMACChars" ]; then
+  # This subnet is a MAC
+  if test -f "\$macFile"; then
+    rm \$macFile
+  fi
+else
+  if echo "\$SUBNET" | grep -q -E ".+/32\$"; then
+    # This subnet is likely an IP address, remove it from the ARP table
+    address=`echo "\$SUBNET" | cut -d '/' -f 1`
+    echo "Unmapping \$address <=> \$mac from ARP table"
+    arp -s "\$address"
+  fi
+fi