network/ifup.sh: arping for static IPv4 addresses

(cherry picked from commit 38180271c587f3053710bf38a6cda829d3a7c00f)

diff --git a/modules.d/40network/ifup.sh b/modules.d/40network/ifup.sh
index ceb5f5cb4bbdfc5a3d5fd7e74569e94c7a64baeb..7da9171bb92a90079fbdac6cbd04256b3e11959d 100755 (executable)
--- a/modules.d/40network/ifup.sh
+++ b/modules.d/40network/ifup.sh
@@ -158,6 +158,10 @@ do_static() {
         ip addr add $ip/$mask ${srv:+peer $srv} dev $netif
         wait_for_ipv6_dad $netif
     else
+        if ! arping -f -q -D -c 2 -I $netif $ip; then
+            warn "Duplicate address detected for $ip for interface $netif."
+            return 1
+        fi
         ip addr flush dev $netif
         ip addr add $ip/$mask ${srv:+peer $srv} brd + dev $netif
     fi