diff --git a/source/firewall/firewall_ipv6.c b/source/firewall/firewall_ipv6.c
index 57f4a705..57421e0c 100644
--- a/source/firewall/firewall_ipv6.c
+++ b/source/firewall/firewall_ipv6.c
@@ -187,10 +187,6 @@ int numifs = sizeof(ifnames) / sizeof(*ifnames);
 #define V6_PORTSCANPROTECT  "v6_PortScanProtect"
 #define V6_IPFLOODDETECT    "v6_IPFloodDetect"
 
-#ifdef _ONESTACK_PRODUCT_REQ_
-#define COSA_DML_DHCPV6_CLIENT_IFNAME                 "erouter0"
-#define COSA_DML_DHCPV6C_PREF_SYSEVENT_NAME           "tr_"COSA_DML_DHCPV6_CLIENT_IFNAME"_dhcpv6_client_v6pref"
-#endif
 /*
  ****************************************************************
  *               IPv6 Firewall                                  *
@@ -496,6 +492,10 @@ void do_ipv6_filter_table(FILE *fp){
    char request[256], response[256], cm_ipv6addr[40];
    unsigned int a[16] = {0};
 #endif
+#if defined (_ONESTACK_PRODUCT_REQ_)
+    char current_wan_interface[64] = {0};
+    char sysevent_name[128] = {0};
+#endif
 	
    fprintf(fp, "*filter\n");
    fprintf(fp, ":INPUT ACCEPT [0:0]\n");
@@ -1263,14 +1263,16 @@ void do_ipv6_filter_table(FILE *fp){
 #ifdef _ONESTACK_PRODUCT_REQ_
       if(isFeatureSupportedInCurrentMode(FEATURE_IPV6_DELEGATION))
       {
-	  sysevent_get(sysevent_fd, sysevent_token, COSA_DML_DHCPV6C_PREF_SYSEVENT_NAME, prefix, sizeof(prefix));
+	 sysevent_get(sysevent_fd, sysevent_token, "current_wan_ifname", current_wan_interface, sizeof(current_wan_interface));
+         snprintf(sysevent_name, sizeof(sysevent_name), "tr_%s_dhcpv6_client_v6pref", current_wan_interface);
+	 sysevent_get(sysevent_fd, sysevent_token, sysevent_name, prefix, sizeof(prefix));
       }
       else
       {
-	  sysevent_get(sysevent_fd, sysevent_token, "ipv6_prefix", prefix, sizeof(prefix));
+	 sysevent_get(sysevent_fd, sysevent_token, "ipv6_prefix", prefix, sizeof(prefix));
       }
 #else
-	  sysevent_get(sysevent_fd, sysevent_token, "ipv6_prefix", prefix, sizeof(prefix));
+	 sysevent_get(sysevent_fd, sysevent_token, "ipv6_prefix", prefix, sizeof(prefix));
 #endif
       }
 
@@ -1278,7 +1280,10 @@ void do_ipv6_filter_table(FILE *fp){
 #ifdef _ONESTACK_PRODUCT_REQ_
       if(isFeatureSupportedInCurrentMode(FEATURE_IPV6_DELEGATION))
       {
-         sysevent_get(sysevent_fd, sysevent_token, COSA_DML_DHCPV6C_PREF_SYSEVENT_NAME, prefix, sizeof(prefix));
+	 sysevent_get(sysevent_fd, sysevent_token, "current_wan_ifname", current_wan_interface, sizeof(current_wan_interface));
+         snprintf(sysevent_name, sizeof(sysevent_name), "tr_%s_dhcpv6_client_v6pref", current_wan_interface);
+         sysevent_get(sysevent_fd, sysevent_token, sysevent_name, prefix, sizeof(prefix));
+
       }
       else
       {
@@ -1300,7 +1305,7 @@ void do_ipv6_filter_table(FILE *fp){
 #if defined (_COSA_FOR_BCI_) || defined (_ONESTACK_PRODUCT_REQ_)
          /* adding forward rule for PD traffic */
 #ifdef _ONESTACK_PRODUCT_REQ_
-      if(isFeatureSupportedInCurrentMode(FEATURE_IPV6_DELEGATION))
+      if (isFeatureSupportedInCurrentMode(FEATURE_IPV6_DELEGATION))
       {
          fprintf(fp, "-A FORWARD -s %s -i %s -j ACCEPT\n", prefix, lan_ifname);
 	 if (strncasecmp(firewall_levelv6, "Custom", strlen("Custom")) == 0)
@@ -2134,6 +2139,10 @@ typedef enum{
 void applyRoutingRules(FILE* fp,ipv6_type type)
 {
        FIREWALL_DEBUG("Entering applyRoutingRules, ipv6_type is %d \n" COMMA type);
+#if defined (_ONESTACK_PRODUCT_REQ_)
+    char current_wan_interface[64] = {0};
+    char sysevent_name[128] = {0};
+#endif
          char prefix[64] ;
          memset(prefix,0,sizeof(prefix));
          int i ;
@@ -2143,20 +2152,37 @@ void applyRoutingRules(FILE* fp,ipv6_type type)
 	 }
          else
 	 {
-#ifdef _ONESTACK_PRODUCT_REQ_
-	     if(isFeatureSupportedInCurrentMode(FEATURE_IPV6_DELEGATION))
+         #ifdef _ONESTACK_PRODUCT_REQ_
+	     if(isFeatureSupportedInCurrentMode(FEATURE_IPV6_DELEGATION)) 
 	     {
-		 sysevent_get(sysevent_fd, sysevent_token, COSA_DML_DHCPV6C_PREF_SYSEVENT_NAME, prefix, sizeof(prefix));
+		 sysevent_get(sysevent_fd, sysevent_token, "current_wan_ifname", current_wan_interface, sizeof(current_wan_interface));
+		 if (current_wan_interface[0] != '\0')
+		 {
+		     snprintf(sysevent_name, sizeof(sysevent_name), "tr_%s_dhcpv6_client_v6pref", current_wan_interface);
+		     sysevent_get(sysevent_fd, sysevent_token, sysevent_name, prefix, sizeof(prefix));
+		 }
+		 else
+		 {
+		     sysevent_get(sysevent_fd, sysevent_token, "ipv6_prefix", prefix, sizeof(prefix));
+		 }
 	     }
 	     else
 	     {
 		 sysevent_get(sysevent_fd, sysevent_token, "ipv6_prefix", prefix, sizeof(prefix));
 	     }
-#else
+         #else
 	     sysevent_get(sysevent_fd, sysevent_token, "ipv6_prefix", prefix, sizeof(prefix));
-#endif
+         #endif
 	 }
-	 if (strlen(prefix) != 0 )
+	 /* Add firewall rules only if prefix is non-empty and, when IPv6 delegation is enabled, current_wan_interface is also non-empty */
+         #ifdef _ONESTACK_PRODUCT_REQ_
+	 if ((strlen(prefix) != 0) &&
+	     (!isFeatureSupportedInCurrentMode(FEATURE_IPV6_DELEGATION) ||
+	      (ULA_IPV6 == type) ||
+	      (strlen(current_wan_interface) != 0)))
+         #else
+	 if (strlen(prefix) != 0)
+         #endif
          {
       char *token_pref =NULL;
          token_pref = strtok(prefix,"/");