diff --git a/core/src/com/cloud/agent/resource/virtualnetwork/ConfigHelper.java b/core/src/com/cloud/agent/resource/virtualnetwork/ConfigHelper.java
index aab966376be..83394ab98b0 100644
--- a/core/src/com/cloud/agent/resource/virtualnetwork/ConfigHelper.java
+++ b/core/src/com/cloud/agent/resource/virtualnetwork/ConfigHelper.java
@@ -516,7 +516,7 @@ public class ConfigHelper {
         String routerGIP = cmd.getAccessDetail(NetworkElementCommand.ROUTER_GUEST_IP);
         String gateway = cmd.getAccessDetail(NetworkElementCommand.GUEST_NETWORK_GATEWAY);
         String cidr = Long.toString(NetUtils.getCidrSize(nic.getNetmask()));
-        String netmask = NetUtils.getSubNet(routerGIP, nic.getNetmask());
+        String netmask = nic.getNetmask();
         String domainName = cmd.getNetworkDomain();
         String dns = cmd.getDefaultDns1();