diff --git a/sample_wg_cfg/wg-internal.conf b/sample_wg_cfg/wg-internal.conf
index b8e43c1..e7193ae 100644
--- a/sample_wg_cfg/wg-internal.conf
+++ b/sample_wg_cfg/wg-internal.conf
@@ -3,9 +3,9 @@ Address = 10.20.30.1/32
 ListenPort = 17968
 PrivateKey = kOd3FVBggwpjD3AlZKXUxNTzJT0+f3MJdUdR8n6ZBn8=
 PostUp = iptables -t nat -A POSTROUTING -o `ip route | awk '/default/ {print $5; exit}'` -j MASQUERADE
-PostUp = ip rule add from `ip route | awk '/default/ {print $3; exit}'` table main
+PostUp = ip rule add from `ip addr show $(ip route | awk '/default/ { print $5 }') | grep "inet" | grep -v "inet6" | head -n 1 | awk '/inet/ {print $2}' | awk -F/ '{print $1}'` table main
 PostDown = iptables -t nat -D POSTROUTING -o `ip route | awk '/default/ {print $5; exit}'` -j MASQUERADE
-PostDown = ip rule del from `ip route | awk '/default/ {print $3; exit}'` table main
+PostDown = ip rule del from `ip addr show $(ip route | awk '/default/ { print $5 }') | grep "inet" | grep -v "inet6" | head -n 1 | awk '/inet/ {print $2}' | awk -F/ '{print $1}'` table main
 
 #external node
 [Peer]