diff --git a/p4src/static-mapping.p4 b/p4src/static-mapping.p4
index 9b5b267..55311f9 100644
--- a/p4src/static-mapping.p4
+++ b/p4src/static-mapping.p4
@@ -334,18 +334,25 @@ Echo or Echo Reply Message
     /********************** ARP ***********************************/
 
     action arp_reply(mac_addr_t mac_addr) {
-        ipv4_addr_t tmp = hdr.arp.src_ipv4_addr;
+        /* swap */
+        ipv4_addr_t ipv4_src = hdr.arp.dst_ipv4_addr;
+        ipv4_addr_t ipv4_dst = hdr.arp.src_ipv4_addr;
+
+        /* swap/add */
+        mac_addr_t mac_src = mac_addr;
+        mac_addr_t mac_dst = hdr.arp.src_mac_addr;
 
         /* fill the ethernet header */
-        hdr.ethernet.src_addr = mac_addr;
-        hdr.ethernet.dst_addr = hdr.arp.src_mac_addr;
+        hdr.ethernet.dst_addr = mac_dst;
+        hdr.ethernet.src_addr = mac_src;
 
         /* fill the arp header */
-        hdr.arp.dst_mac_addr  = hdr.arp.src_mac_addr;
-        hdr.arp.dst_ipv4_addr = tmp;
+        hdr.arp.dst_mac_addr  = mac_dst;
+        hdr.arp.src_mac_addr  = mac_src;
 
-        hdr.arp.src_mac_addr = mac_addr;
-        hdr.arp.src_ipv4_addr = hdr.arp.dst_ipv4_addr;
+        /* swapping */
+        hdr.arp.dst_ipv4_addr = ipv4_src;
+        hdr.arp.src_ipv4_addr = ipv4_dst;
 
         hdr.arp.opcode = ARP_REPLY;
     }