diff --git a/p4src/headers.p4 b/p4src/headers.p4
new file mode 100644
index 0000000..290dff1
--- /dev/null
+++ b/p4src/headers.p4
@@ -0,0 +1,81 @@
+/* -*- P4_16 -*- */
+#ifndef HEADERS_P4
+#define HEADERS_P4
+
+#include <core.p4>
+#include <v1model.p4>
+
+typedef bit<48>  mac_addr_t;
+typedef bit<32>  ipv4_addr_t;
+typedef bit<128> ipv6_addr_t;
+typedef bit<9>   port_t;
+
+
+const bit<16> TYPE_IPV4  = 0x0800;
+const bit<16> TYPE_IPV6  = 0x86DD;
+const bit<8>  TYPE_TCP  = 6;
+
+
+header ethernet_t {
+    mac_addr_t dst_addr;
+    mac_addr_t src_addr;
+    bit<16>    ethertype;
+}
+
+header ipv4_t {
+    bit<4>      version;
+    bit<4>      ihl;
+    bit<6>      diff_serv;
+    bit<2>      ecn;
+    bit<16>     totalLen;
+    bit<16>     identification;
+    bit<3>      flags;
+    bit<13>     fragOffset;
+    bit<8>      ttl;
+    bit<8>      protocol;
+    bit<16>     hdrChecksum;
+    ipv4_addr_t src_addr;
+    ipv4_addr_t dst_addr;
+}
+
+/* https://en.wikipedia.org/wiki/IPv6_packet */
+header ipv6_t {
+    bit<4>      version;
+    bit<8>      traffic_class;
+    bit<20>     flow_label;
+    bit<16>     payload_length;
+    bit<8>      next_header;
+    bit<8>      hop_limit;
+    ipv6_addr_t src_addr;
+    ipv6_addr_t dst_addr;
+}
+
+header tcp_t{
+    bit<16> src_port;
+    bit<16> dst_port;
+    int<32> seqNo;
+    int<32> ackNo;
+    bit<4>  data_offset;
+    bit<4>  res;
+    bit<1>  cwr;
+    bit<1>  ece;
+    bit<1>  urg;
+    bit<1>  ack;
+    bit<1>  psh;
+    bit<1>  rst;
+    bit<1>  syn;
+    bit<1>  fin;
+    bit<16> window;
+    bit<16> checksum;
+    bit<16> urgentPtr;
+}
+
+struct headers {
+    ethernet_t       ethernet;
+    ipv4_t	         ipv4;
+    ipv6_t	         ipv6;
+    tcp_t	         tcp;
+    rewrite_header_t rewrite;
+}
+
+#endif
\ No newline at end of file