diff --git a/doc/plan.org b/doc/plan.org
index 46c2b45..6a78912 100644
--- a/doc/plan.org
+++ b/doc/plan.org
@@ -422,6 +422,15 @@
 |            |                                                                            |       |
 |            |                                                                            |       |
 | 2019-07-11 |                                                                            |       |
+|            | Meeting Laurent                                                            |       |
+|            |                                                                            |       |
+|            | - Delta diff in P4 from v4 -> v6: checksum working                         |       |
+|            | - Investigating why NDP doesn't work                                       |       |
+|            |                                                                            |       |
+|            | - compile to netpfga: open impl error                                      |       |
+|            | - netpfga: icmp6/ndp might not work                                        |       |
+|            |                                                                            |       |
+|            |                                                                            |       |
 |            | Integrated org-documentation into latex / export working                   |       |
 |            | https://bastibe.de/2014-09-23-org-cite.html                                |       |
 |            | http://viveks.info/org-mode-academic-writing-bibliographies-org-ref/       |       |
diff --git a/p4src/checksum_bmv2.p4 b/p4src/checksum_bmv2.p4
new file mode 100644
index 0000000..4a0cbe4
--- /dev/null
+++ b/p4src/checksum_bmv2.p4
@@ -0,0 +1,176 @@
+/* -*- P4_16 -*- */
+#ifndef CHECKSUMS_P4
+#define CHECKSUMS_P4
+
+#include <core.p4>
+#include <v1model.p4>
+
+#include "headers.p4"
+
+update_checksum_with_payload(meta.chk_icmp6 == 1,
+	{
+        hdr.ipv6.src_addr,         /* 128 */
+		hdr.ipv6.dst_addr,         /* 128 */
+        meta.cast_length,          /* 32 */
+        24w0,                      /* 24 0's */
+        PROTO_ICMP6,               /* 8 */
+        hdr.icmp6.type,            /* 8 */
+        hdr.icmp6.code             /* 8 */
+    },
+    hdr.icmp6.checksum,
+    HashAlgorithm.csum16
+);
+
+/* checksumming for icmp6_na_ns_option */
+update_checksum_with_payload(meta.chk_icmp6_na_ns == 1,
+	{
+        hdr.ipv6.src_addr,         /* 128 */
+		hdr.ipv6.dst_addr,         /* 128 */
+        meta.cast_length,          /* 32 */
+        24w0,                      /* 24 0's */
+        PROTO_ICMP6,               /* 8 */
+        hdr.icmp6.type,            /* 8 */
+        hdr.icmp6.code,            /* 8 */
+
+        hdr.icmp6_na_ns.router,
+        hdr.icmp6_na_ns.solicitated,
+        hdr.icmp6_na_ns.override,
+        hdr.icmp6_na_ns.reserved,
+        hdr.icmp6_na_ns.target_addr,
+
+        hdr.icmp6_option_link_layer_addr.type,
+        hdr.icmp6_option_link_layer_addr.ll_length,
+        hdr.icmp6_option_link_layer_addr.mac_addr
+    },
+    hdr.icmp6.checksum,
+    HashAlgorithm.csum16
+);
+
+update_checksum_with_payload(meta.chk_icmp == 1,
+	{
+        hdr.icmp.type,
+        hdr.icmp.code
+    },
+    hdr.icmp.checksum,
+    HashAlgorithm.csum16
+);
+
+update_checksum(meta.chk_ipv4 == 1,
+    {
+        hdr.ipv4.version,
+	    hdr.ipv4.ihl,
+        hdr.ipv4.diff_serv,
+        hdr.ipv4.ecn,
+        hdr.ipv4.totalLen,
+        hdr.ipv4.identification,
+        hdr.ipv4.flags,
+        hdr.ipv4.fragOffset,
+        hdr.ipv4.ttl,
+        hdr.ipv4.protocol,
+        hdr.ipv4.src_addr,
+        hdr.ipv4.dst_addr
+    },
+    hdr.ipv4.hdrChecksum,
+    HashAlgorithm.csum16
+);
+
+update_checksum_with_payload(meta.chk_udp_v4 == 1,
+    {
+        hdr.ipv4.src_addr,
+        hdr.ipv4.dst_addr,
+        8w0,
+        hdr.ipv4.protocol,
+		meta.length_without_ip_header,
+
+		// UDP header
+        hdr.udp.src_port,
+        hdr.udp.dst_port,
+        hdr.udp.payload_length
+    },
+    hdr.udp.checksum,
+    HashAlgorithm.csum16
+);
+
+update_checksum_with_payload(meta.chk_udp_v6 == 1,
+    {
+        hdr.ipv6.src_addr,               /* 128 */
+        hdr.ipv6.dst_addr,               /* 128 */
+		meta.length_without_ip_header,   /* 32 */
+        24w0,                            /* 24 */
+		hdr.ipv6.next_header,            /* 8 */
+        /* total: 324 */
+
+		// UDP header
+        hdr.udp.src_port,                /* 16 */
+        hdr.udp.dst_port,                /* 16 */
+        hdr.udp.payload_length           /* 16 */
+        /* all: 372 */
+
+    },
+    hdr.udp.checksum,
+    HashAlgorithm.csum16
+);
+
+update_checksum_with_payload(meta.chk_tcp_v4 == 1,
+	{
+        hdr.ipv4.src_addr,
+		hdr.ipv4.dst_addr,
+		8w0,
+		hdr.ipv4.protocol,
+        meta.length_without_ip_header,
+
+		// TCP header
+		hdr.tcp.src_port,
+		hdr.tcp.dst_port,
+		hdr.tcp.seqNo,
+		hdr.tcp.ackNo,
+		hdr.tcp.data_offset,
+		hdr.tcp.res,
+		hdr.tcp.cwr,
+		hdr.tcp.ece,
+		hdr.tcp.urg,
+		hdr.tcp.ack,
+		hdr.tcp.psh,
+		hdr.tcp.rst,
+		hdr.tcp.syn,
+		hdr.tcp.fin,
+		hdr.tcp.window,
+		hdr.tcp.urgentPtr
+	},
+	hdr.tcp.checksum,
+	HashAlgorithm.csum16
+);
+
+update_checksum_with_payload(meta.chk_tcp_v6 == 1,
+			{
+        hdr.ipv6.src_addr,
+		hdr.ipv6.dst_addr,
+		meta.length_without_ip_header,
+		24w0,
+		hdr.ipv6.next_header,
+
+		// TCP header
+		hdr.tcp.src_port,
+		hdr.tcp.dst_port,
+		hdr.tcp.seqNo,
+		hdr.tcp.ackNo,
+		hdr.tcp.data_offset,
+		hdr.tcp.res,
+		hdr.tcp.cwr,
+		hdr.tcp.ece,
+		hdr.tcp.urg,
+		hdr.tcp.ack,
+		hdr.tcp.psh,
+		hdr.tcp.rst,
+		hdr.tcp.syn,
+		hdr.tcp.fin,
+		hdr.tcp.window,
+		hdr.tcp.urgentPtr
+	},
+	hdr.tcp.checksum,
+	HashAlgorithm.csum16);
+}
+
+
+
+#endif
diff --git a/p4src/checksum_diff.p4 b/p4src/checksum_diff.p4
index 12e925a..b49bd96 100644
--- a/p4src/checksum_diff.p4
+++ b/p4src/checksum_diff.p4
@@ -142,19 +142,9 @@ control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
 
 control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
     apply {
-        update_checksum(meta.chk_icmp6 == 1,
-		 	{
-                hdr.ipv6.src_addr,         /* 128 */
-		 		hdr.ipv6.dst_addr,         /* 128 */
-                meta.cast_length,          /* 32 */
-                24w0,                      /* 24 0's */
-                PROTO_ICMP6,               /* 8 */
-                hdr.icmp6.type,            /* 8 */
-                hdr.icmp6.code             /* 8 */
-            },
-            hdr.icmp6.checksum,
-            HashAlgorithm.csum16
-        );
+        #ifndef _SUME_SWITCH_P4_
+        #include "checksum_bmv2.p4"
+        #endif
     }
 }
 
diff --git a/p4src/checksums.p4 b/p4src/checksums.p4
deleted file mode 100644
index e22da18..0000000
--- a/p4src/checksums.p4
+++ /dev/null
@@ -1,191 +0,0 @@
-/* -*- P4_16 -*- */
-#ifndef CHECKSUMS_P4
-#define CHECKSUMS_P4
-
-#include <core.p4>
-#include <v1model.p4>
-
-#include "headers.p4"
-
-/*************************************************************************
-*************   C H E C K S U M    V E R I F I C A T I O N   *************
-*************************************************************************/
-
-control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
-    apply {}
-}
-
-/*************************************************************************
-**************   C H E C K S U M    C O M P U T A T I O N   **************
-*************************************************************************/
-
-control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
-    apply {
-        update_checksum_with_payload(meta.chk_icmp6 == 1,
-		 	{
-                hdr.ipv6.src_addr,         /* 128 */
-		 		hdr.ipv6.dst_addr,         /* 128 */
-                meta.cast_length,          /* 32 */
-                24w0,                      /* 24 0's */
-                PROTO_ICMP6,               /* 8 */
-                hdr.icmp6.type,            /* 8 */
-                hdr.icmp6.code             /* 8 */
-            },
-            hdr.icmp6.checksum,
-            HashAlgorithm.csum16
-        );
-
-        /* checksumming for icmp6_na_ns_option */
-        update_checksum_with_payload(meta.chk_icmp6_na_ns == 1,
-		 	{
-                hdr.ipv6.src_addr,         /* 128 */
-		 		hdr.ipv6.dst_addr,         /* 128 */
-                meta.cast_length,          /* 32 */
-                24w0,                      /* 24 0's */
-                PROTO_ICMP6,               /* 8 */
-                hdr.icmp6.type,            /* 8 */
-                hdr.icmp6.code,            /* 8 */
-
-                hdr.icmp6_na_ns.router,
-                hdr.icmp6_na_ns.solicitated,
-                hdr.icmp6_na_ns.override,
-                hdr.icmp6_na_ns.reserved,
-                hdr.icmp6_na_ns.target_addr,
-
-                hdr.icmp6_option_link_layer_addr.type,
-                hdr.icmp6_option_link_layer_addr.ll_length,
-                hdr.icmp6_option_link_layer_addr.mac_addr
-            },
-            hdr.icmp6.checksum,
-            HashAlgorithm.csum16
-        );
-
-        update_checksum_with_payload(meta.chk_icmp == 1,
-		 	{
-                hdr.icmp.type,
-                hdr.icmp.code
-            },
-            hdr.icmp.checksum,
-            HashAlgorithm.csum16
-        );
-
-	    update_checksum(meta.chk_ipv4 == 1,
-            {
-                hdr.ipv4.version,
-	            hdr.ipv4.ihl,
-                hdr.ipv4.diff_serv,
-                hdr.ipv4.ecn,
-                hdr.ipv4.totalLen,
-                hdr.ipv4.identification,
-                hdr.ipv4.flags,
-                hdr.ipv4.fragOffset,
-                hdr.ipv4.ttl,
-                hdr.ipv4.protocol,
-                hdr.ipv4.src_addr,
-                hdr.ipv4.dst_addr
-            },
-            hdr.ipv4.hdrChecksum,
-            HashAlgorithm.csum16
-        );
-
-	    update_checksum_with_payload(meta.chk_udp_v4 == 1,
-            {
-                hdr.ipv4.src_addr,
-                hdr.ipv4.dst_addr,
-                8w0,
-                hdr.ipv4.protocol,
-			    meta.length_without_ip_header,
-
-				// UDP header
-                hdr.udp.src_port,
-                hdr.udp.dst_port,
-                hdr.udp.payload_length
-            },
-            hdr.udp.checksum,
-            HashAlgorithm.csum16
-        );
-
-	    update_checksum_with_payload(meta.chk_udp_v6 == 1,
-            {
-                hdr.ipv6.src_addr,               /* 128 */
-                hdr.ipv6.dst_addr,               /* 128 */
-			    meta.length_without_ip_header,   /* 32 */
-                24w0,                            /* 24 */
-				hdr.ipv6.next_header,            /* 8 */
-                                                 /* total: 324 */
-
-				// UDP header
-                hdr.udp.src_port,                /* 16 */
-                hdr.udp.dst_port,                /* 16 */
-                hdr.udp.payload_length           /* 16 */
-                                                 /* all: 372 */
-
-            },
-            hdr.udp.checksum,
-            HashAlgorithm.csum16
-        );
-
-		update_checksum_with_payload(meta.chk_tcp_v4 == 1,
-			{
-                hdr.ipv4.src_addr,
-				hdr.ipv4.dst_addr,
-				8w0,
-				hdr.ipv4.protocol,
-                meta.length_without_ip_header,
-
-				// TCP header
-				hdr.tcp.src_port,
-				hdr.tcp.dst_port,
-				hdr.tcp.seqNo,
-				hdr.tcp.ackNo,
-				hdr.tcp.data_offset,
-				hdr.tcp.res,
-				hdr.tcp.cwr,
-				hdr.tcp.ece,
-				hdr.tcp.urg,
-				hdr.tcp.ack,
-				hdr.tcp.psh,
-				hdr.tcp.rst,
-				hdr.tcp.syn,
-				hdr.tcp.fin,
-				hdr.tcp.window,
-				hdr.tcp.urgentPtr
-			},
-			hdr.tcp.checksum,
-			HashAlgorithm.csum16
-        );
-
-		update_checksum_with_payload(meta.chk_tcp_v6 == 1,
-			{
-                hdr.ipv6.src_addr,
-				hdr.ipv6.dst_addr,
-			    meta.length_without_ip_header,
-				24w0,
-				hdr.ipv6.next_header,
-
-				// TCP header
-				hdr.tcp.src_port,
-				hdr.tcp.dst_port,
-				hdr.tcp.seqNo,
-				hdr.tcp.ackNo,
-				hdr.tcp.data_offset,
-				hdr.tcp.res,
-				hdr.tcp.cwr,
-				hdr.tcp.ece,
-				hdr.tcp.urg,
-				hdr.tcp.ack,
-				hdr.tcp.psh,
-				hdr.tcp.rst,
-				hdr.tcp.syn,
-				hdr.tcp.fin,
-				hdr.tcp.window,
-				hdr.tcp.urgentPtr
-			},
-			hdr.tcp.checksum,
-			HashAlgorithm.csum16);
-
-    }
-}
-
-
-#endif
diff --git a/p4src/nat64.p4 b/p4src/nat64.p4
index df9e8d2..1e66fd5 100644
--- a/p4src/nat64.p4
+++ b/p4src/nat64.p4
@@ -626,6 +626,22 @@ control MyEgress(inout headers hdr,
 	}
 }
 
+/*************************************************************************
+*************   C H E C K S U M    V E R I F I C A T I O N   *************
+*************************************************************************/
+
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
+    apply {}
+}
+
+/*************************************************************************
+**************   C H E C K S U M    C O M P U T A T I O N   **************
+*************************************************************************/
+
+control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
+    #include "checksum_bmv2.p4"
+}
+
 /*************************************************************************
 ***********************  S W I T C H  *******************************
 *************************************************************************/