diff --git a/doc/plan.org b/doc/plan.org
index 44babec..cb8ecb9 100644
--- a/doc/plan.org
+++ b/doc/plan.org
@@ -185,7 +185,7 @@
 |            |                                                                            |       |
 |            | Added arp handling                                                         |       |
 |            | Added icmp handling                                                        |       |
-|            | Static                                                                     |       |
+|            | Need to setup hardware addresses -> in theor resolution -> hardcoded atm   |       |
 |            |                                                                            |       |
 |            |                                                                            |       |
 | 2019-04-04 | NAT64 1:1 table ICMP, ICMPv6 working                                       |       |
@@ -704,7 +704,16 @@ INFO:main:unhandled reassambled=<Ether  dst=00:00:0a:00:00:42 src=00:00:0a:00:00
 According to Edgar this should not be seen anyway.
 ****** DONE Calculate ICMP checksum
 ****** DONE Check field lengths
-****** TODO Fix resolve / mac addresses -> ethernet is wrong!
+****** DONE Fix resolve / mac addresses -> ethernet is wrong!
+INFO:main:unhandled reassambled=<Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x86dd |<IPv6  version=6 tc=0 fl=0 plen=32 nh=ICMPv6 hlim=255 src=fe80::200:aff:fe00:1 dst=ff02::1:ff00:42 |<ICMPv6ND_NS  type=Neighbor Solicitation code=0 cksum=0x37df res=0 tgt=2001:db8::42 |<ICMPv6NDOptSrcLLAddr  type=1 len=1 lladdr=00:00:0a:00:00:01 |>>>> from table TABLE_V6_NETWORKS
+INFO:main:unhandled reassambled=<Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x86dd |<IPv6  version=6 tc=0 fl=0 plen=32 nh=ICMPv6 hlim=255 src=fe80::200:aff:fe00:1 dst=ff02::1:ff00:42 |<ICMPv6ND_NS  type=Neighbor Solicitation code=0 cksum=0x37df res=0 tgt=2001:db8::42 |<ICMPv6NDOptSrcLLAddr  type=1 len=1 lladdr=00:00:0a:00:00:01 |>>>> from table TABLE_V6_NETWORKS
+INFO:main:unhandled reassambled=<Ether  dst=33:33:ff:00:00:42 src=00:00:0a:00:00:01 type=0x86dd |<IPv6  version=6 tc=0 fl=0 plen=32 nh=ICMPv6 hlim=255 src=2001:db8::1 dst=ff02::1:ff00:42 |<ICMPv6ND_NS  type=Neighbor Solicitation code=0 cksum=0x13a7 res=0 tgt=2001:db8::42 |<ICMPv6NDOptSrcLLAddr  type=1 len=1 lladdr=00:00:0a:00:00:01 |>>>> from table TABLE_V6_NETWORKS
+
+According to pcap/static_nat64-2019-04-03-0932-h3.pcap ethernet frame
+looks good. Still no reply / reaction from host h3.
+****** TODO Fix IPv4 header checksum // wrong according to wireshark
+When & how to update?
+
 ***** TODO transform protocol specific: icmp -> icmp6
 ****** DONE Make switch answer IPv4 icmp echo request for
 ******* DONE Make switch respond to ARP
diff --git a/p4src/checksums.p4 b/p4src/checksums.p4
index 798e974..ce2da97 100644
--- a/p4src/checksums.p4
+++ b/p4src/checksums.p4
@@ -69,6 +69,24 @@ control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
             hdr.icmp.checksum,
             HashAlgorithm.csum16
         );
+
+	    update_checksum(meta.chk_ipv4 == 1,
+            {
+                hdr.ipv4.version,
+	            hdr.ipv4.ihl,
+                hdr.ipv4.dscp,
+                hdr.ipv4.ecn,
+                hdr.ipv4.totalLen,
+                hdr.ipv4.identification,
+                hdr.ipv4.flags,
+                hdr.ipv4.fragOffset,
+                hdr.ipv4.ttl,
+                hdr.ipv4.protocol,
+                hdr.ipv4.srcAddr,
+                hdr.ipv4.dstAddr
+            },
+            hdr.ipv4.hdrChecksum,
+            HashAlgorithm.csum16);
     }
 }
 
diff --git a/p4src/headers.p4 b/p4src/headers.p4
index 1a25d0c..8c48927 100644
--- a/p4src/headers.p4
+++ b/p4src/headers.p4
@@ -211,6 +211,7 @@ struct metadata {
     bit<1> chk_icmp6_na_ns;
     bit<1> chk_icmp6;
     bit<1> chk_icmp;
+    bit<1> chk_ipv4;
 
     bit<16> tcp_length;
     bit<32> cast_length;
diff --git a/p4src/static-mapping.p4 b/p4src/static-mapping.p4
index c9a1880..c35d31b 100644
--- a/p4src/static-mapping.p4
+++ b/p4src/static-mapping.p4
@@ -74,6 +74,7 @@ control MyIngress(inout headers hdr,
     /* NAT64 protocol unspecific changes */
     action nat64_generic(ipv4_addr_t src, ipv4_addr_t dst) {
 		hdr.ipv4.setValid();
+        meta.chk_ipv4 = 1; /* need to calculate the hdrchecksum */
 
         /* Stuff that might need to be fixed */
         hdr.ipv4.version        = (bit<4>)4;