diff --git a/src/vnet/adj/adj_dp.h b/src/vnet/adj/adj_dp.h
index aff1a2b..186044b 100644
--- a/src/vnet/adj/adj_dp.h
+++ b/src/vnet/adj/adj_dp.h
@@ -36,22 +36,36 @@
   ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));
 
   if (PREDICT_TRUE(TUNNEL_ENCAP_DECAP_FLAG_NONE == flags))
-  {
-      ip_csum_t sum;
-      u16 old,new;
-
-      old = 0;
-      new = ip4->length;
-
-      sum = ip4->checksum;
-      sum = ip_csum_update (sum, old, new, ip4_header_t, length);
-      ip4->checksum = ip_csum_fold (sum);
-  }
+    {
+      if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+       {
+         vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip4 - b->data;
+         vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_TNL_IPIP |
+                                     VNET_BUFFER_OFFLOAD_F_OUTER_IP_CKSUM);
+       }
+      else
+       {
+         ip_csum_t sum;
+         u16 old,new;
+         old = 0;
+         new = ip4->length;
+         sum = ip4->checksum;
+         sum = ip_csum_update (sum, old, new, ip4_header_t, length);
+         ip4->checksum = ip_csum_fold (sum);
+       }
+    }
   else
-  {
+    {
       tunnel_encap_fixup_4o4 (flags, ip4 + 1, ip4);
-      ip4->checksum = ip4_header_checksum (ip4);
-  }
+      if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+       {
+         vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip4 - b->data;
+         vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_TNL_IPIP |
+                                     VNET_BUFFER_OFFLOAD_F_OUTER_IP_CKSUM);
+       }
+      else
+        ip4->checksum = ip4_header_checksum (ip4);
+    }
 }
 
 static_always_inline void
diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index eb2b7ee..e85c888 100644
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -2223,9 +2223,6 @@
 						adj0->ia_cfg_index);
 
 	  next[0] = next_index;
-	  if (is_midchain)
-	    vnet_calc_checksums_inline (vm, b[0], 1 /* is_ip4 */ ,
-					0 /* is_ip6 */ );
 	}
       else
 	{
@@ -2248,9 +2245,6 @@
 						&next_index, b[1],
 						adj1->ia_cfg_index);
 	  next[1] = next_index;
-	  if (is_midchain)
-	    vnet_calc_checksums_inline (vm, b[1], 1 /* is_ip4 */ ,
-					0 /* is_ip6 */ );
 	}
       else
 	{
@@ -2400,9 +2394,6 @@
 
 	  if (is_midchain)
 	    {
-	      vnet_calc_checksums_inline (vm, b[0], 1 /* is_ip4 */ ,
-					  0 /* is_ip6 */ );
-
 	      /* Guess we are only writing on ipv4 header. */
 	      vnet_rewrite_one_header (adj0[0], ip0, sizeof (ip4_header_t));
 	    }
@@ -2506,10 +2497,6 @@
 
 	  if (is_midchain)
 	    {
-	      /* this acts on the packet that is about to be encapped */
-	      vnet_calc_checksums_inline (vm, b[0], 1 /* is_ip4 */ ,
-					  0 /* is_ip6 */ );
-
 	      /* Guess we are only writing on ipv4 header. */
 	      vnet_rewrite_one_header (adj0[0], ip0, sizeof (ip4_header_t));
 	    }
diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index 1f7fc3f..06c473b 100644
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -1971,13 +1971,6 @@
 
 	  if (is_midchain)
 	    {
-	      /* before we paint on the next header, update the L4
-	       * checksums if required, since there's no offload on a tunnel */
-	      vnet_calc_checksums_inline (vm, p0, 0 /* is_ip4 */ ,
-					  1 /* is_ip6 */ );
-	      vnet_calc_checksums_inline (vm, p1, 0 /* is_ip4 */ ,
-					  1 /* is_ip6 */ );
-
 	      /* Guess we are only writing on ipv6 header. */
 	      vnet_rewrite_two_headers (adj0[0], adj1[0],
 					ip0, ip1, sizeof (ip6_header_t));
@@ -2071,9 +2064,6 @@
 
 	  if (is_midchain)
 	    {
-	      vnet_calc_checksums_inline (vm, p0, 0 /* is_ip4 */ ,
-					  1 /* is_ip6 */ );
-
 	      /* Guess we are only writing on ip6 header. */
 	      vnet_rewrite_one_header (adj0[0], ip0, sizeof (ip6_header_t));
 	    }
diff --git a/src/vnet/ipip/ipip.c b/src/vnet/ipip/ipip.c
index ec329e2..aaf2146 100644
--- a/src/vnet/ipip/ipip.c
+++ b/src/vnet/ipip/ipip.c
@@ -148,7 +148,14 @@
   ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));
   tunnel_encap_fixup_6o4 (flags, ((ip6_header_t *) (ip4 + 1)), ip4);
 
-  ip4->checksum = ip4_header_checksum (ip4);
+  if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+    {
+      vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip4 - b->data;
+      vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_OUTER_IP_CKSUM |
+					  VNET_BUFFER_OFFLOAD_F_TNL_IPIP);
+    }
+  else
+    ip4->checksum = ip4_header_checksum (ip4);
 }
 
 static void
@@ -164,7 +171,14 @@
   ip4->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));
   tunnel_encap_fixup_4o4 (flags, ip4 + 1, ip4);
 
-  ip4->checksum = ip4_header_checksum (ip4);
+  if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+    {
+      vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip4 - b->data;
+      vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_OUTER_IP_CKSUM |
+					  VNET_BUFFER_OFFLOAD_F_TNL_IPIP);
+    }
+  else
+    ip4->checksum = ip4_header_checksum (ip4);
 }
 
 static void
@@ -185,6 +199,12 @@
     clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) -
 			  sizeof (*ip6));
   tunnel_encap_fixup_4o6 (flags, b, ((ip4_header_t *) (ip6 + 1)), ip6);
+
+  if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+    {
+      vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip6 - b->data;
+      vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_TNL_IPIP);
+    }
 }
 
 static void
@@ -205,6 +225,12 @@
     clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) -
 			  sizeof (*ip6));
   tunnel_encap_fixup_6o6 (flags, ip6 + 1, ip6);
+
+  if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+    {
+      vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip6 - b->data;
+      vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_TNL_IPIP);
+    }
 }
 
 static void
@@ -226,6 +252,12 @@
     clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) - sizeof (*ip6));
   tunnel_encap_fixup_mplso6 (flags, b, (mpls_unicast_header_t *) (ip6 + 1),
 			     ip6);
+
+  if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+    {
+      vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip6 - b->data;
+      vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_TNL_IPIP);
+    }
 }
 
 static void
@@ -245,7 +277,15 @@
   ip4->length =
     clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) - sizeof (*ip4));
   tunnel_encap_fixup_mplso4 (flags, (mpls_unicast_header_t *) (ip4 + 1), ip4);
-  ip4->checksum = ip4_header_checksum (ip4);
+
+  if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_GSO))
+    {
+      vnet_buffer2 (b)->outer_l3_hdr_offset = (u8 *) ip4 - b->data;
+      vnet_buffer_offload_flags_set (b, VNET_BUFFER_OFFLOAD_F_OUTER_IP_CKSUM |
+					  VNET_BUFFER_OFFLOAD_F_TNL_IPIP);
+    }
+  else
+    ip4->checksum = ip4_header_checksum (ip4);
 }
 
 static void
diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index d3a06dc..dd47053 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -18,6 +18,7 @@
 #include <vnet/vnet.h>
 #include <vnet/api_errno.h>
 #include <vnet/ip/ip.h>
+#include <vnet/interface_output.h>
 
 #include <vnet/crypto/crypto.h>
 
@@ -148,11 +149,9 @@
   if (is_transport)
     {
       u8 prot = is_udp ? IP_PROTOCOL_UDP : IP_PROTOCOL_IPSEC_ESP;
-
-      sum = ip_csum_update (ip4->checksum, ip4->protocol,
-			    prot, ip4_header_t, protocol);
+      sum = ip_csum_update (ip4->checksum, ip4->protocol, prot, ip4_header_t,
+			    protocol);
       ip4->protocol = prot;
-
       sum = ip_csum_update (sum, old_len, len, ip4_header_t, length);
     }
   else
@@ -663,6 +662,10 @@
 			 CLIB_CACHE_LINE_BYTES, LOAD);
 	}
 
+      vnet_calc_checksums_inline (vm, b[0], b[0]->flags & VNET_BUFFER_F_IS_IP4,
+				  b[0]->flags & VNET_BUFFER_F_IS_IP6);
+      vnet_calc_outer_checksums_inline (vm, b[0]);
+
       if (is_tun)
 	{
 	  /* we are on a ipsec tunnel's feature arc */
diff --git a/test/test_gso.py b/test/test_gso.py
index 2c8250e..78c5c73 100644
--- a/test/test_gso.py
+++ b/test/test_gso.py
@@ -11,6 +11,7 @@
 import unittest
 
 from scapy.packet import Raw
+from scapy.layers.l2 import GRE
 from scapy.layers.inet6 import IPv6, Ether, IP, ICMPv6PacketTooBig
 from scapy.layers.inet6 import ipv6nh, IPerror6
 from scapy.layers.inet import TCP, ICMP
@@ -23,6 +24,7 @@
 from vpp_ip_route import VppIpRoute, VppRoutePath, FibPathProto
 from vpp_ipip_tun_interface import VppIpIpTunInterface
 from vpp_vxlan_tunnel import VppVxlanTunnel
+from vpp_gre_interface import VppGreInterface
 
 from vpp_ipsec import VppIpsecSA, VppIpsecTunProtect
 from template_ipsec import (
@@ -89,6 +91,9 @@
             self, self.pg0, self.pg0.local_ip6, self.pg0.remote_ip6
         )
 
+        self.gre4 = VppGreInterface(self, self.pg0.local_ip4, self.pg0.remote_ip4)
+        self.gre6 = VppGreInterface(self, self.pg0.local_ip6, self.pg0.remote_ip6)
+
     def tearDown(self):
         super(TestGSO, self).tearDown()
         if not self.vpp_dead:
@@ -804,6 +809,202 @@
             sw_if_index=self.pg0.sw_if_index, enable_disable=0
         )
 
+    def test_gso_gre(self):
+        """GSO GRE test"""
+        #
+        # Send jumbo frame with gso enabled only on gre tunnel interface.
+        # create GRE tunnel on VPP pg0.
+        #
+
+        #
+        # create gre 4 tunnel
+        #
+        self.gre4.add_vpp_config()
+        self.gre4.admin_up()
+        self.gre4.config_ip4()
+
+        #
+        # Add a route that resolves the tunnel's destination
+        #
+        # Add IPv4 routes via tunnel interface
+        self.ip4_via_gre4_tunnel = VppIpRoute(
+            self,
+            "172.16.10.0",
+            24,
+            [
+                VppRoutePath(
+                    "0.0.0.0",
+                    self.gre4.sw_if_index,
+                    proto=FibPathProto.FIB_PATH_NH_PROTO_IP4,
+                )
+            ],
+        )
+        self.ip4_via_gre4_tunnel.add_vpp_config()
+
+        pgre4 = (
+            Ether(src=self.pg2.remote_mac, dst="02:fe:60:1e:a2:79")
+            / IP(src=self.pg2.remote_ip4, dst="172.16.10.3", flags="DF")
+            / TCP(sport=1234, dport=1234)
+            / Raw(b"\xa5" * 65200)
+        )
+
+        # test when GSO segmentation is disabled, Packets are truncated
+        rxs = self.send_and_expect(self.pg2, 5 * [pgre4], self.pg0, 5)
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg0.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg0.remote_mac)
+            self.assertEqual(rx[IP].src, self.pg0.local_ip4)
+            self.assertEqual(rx[IP].dst, self.pg0.remote_ip4)
+            self.assert_ip_checksum_valid(rx)
+            self.assertEqual(rx[IP].proto, 0x2F)  # GRE encap
+            self.assertEqual(rx[GRE].proto, 0x0800)  # IPv4
+            inner = rx[GRE].payload
+            self.assertNotEqual(rx[IP].len - 20 - 4, len(inner))
+            self.assertEqual(inner[IP].src, self.pg2.remote_ip4)
+            self.assertEqual(inner[IP].dst, "172.16.10.3")
+            self.assert_ip_checksum_valid(inner)
+            payload_len = inner[IP].len - 20 - 20
+            self.assertEqual(payload_len, 65200)
+            # truncated packet to MTU size
+            self.assertNotEqual(payload_len, len(inner[Raw]))
+
+        # enable the GSO segmentation on GRE tunnel
+        self.vapi.feature_gso_enable_disable(
+            sw_if_index=self.gre4.sw_if_index, enable_disable=1
+        )
+
+        # test again, this time payload will be chuncked to GSO size (i.e. 1448)
+        rxs = self.send_and_expect(self.pg2, 5 * [pgre4], self.pg0, 225)
+        size = 0
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg0.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg0.remote_mac)
+            self.assertEqual(rx[IP].src, self.pg0.local_ip4)
+            self.assertEqual(rx[IP].dst, self.pg0.remote_ip4)
+            self.assert_ip_checksum_valid(rx)
+            self.assertEqual(rx[IP].proto, 0x2F)  # GRE encap
+            self.assertEqual(rx[GRE].proto, 0x0800)  # IPv4
+            inner = rx[GRE].payload
+            self.assertEqual(rx[IP].len - 20 - 4, len(inner))
+            self.assertEqual(inner[IP].src, self.pg2.remote_ip4)
+            self.assertEqual(inner[IP].dst, "172.16.10.3")
+            self.assert_ip_checksum_valid(inner)
+            self.assert_tcp_checksum_valid(inner)
+            payload_len = inner[IP].len - 20 - 20
+            self.assertEqual(payload_len, len(inner[Raw]))
+            size += payload_len
+        self.assertEqual(size, 65200 * 5)
+
+        # Disable the GSO segmentation on GRE tunnel
+        self.vapi.feature_gso_enable_disable(
+            sw_if_index=self.gre4.sw_if_index, enable_disable=0
+        )
+
+        # test again when GSO segmentation is disabled, Packets are truncated
+        rxs = self.send_and_expect(self.pg2, 5 * [pgre4], self.pg0, 5)
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg0.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg0.remote_mac)
+            self.assertEqual(rx[IP].src, self.pg0.local_ip4)
+            self.assertEqual(rx[IP].dst, self.pg0.remote_ip4)
+            self.assert_ip_checksum_valid(rx)
+            self.assertEqual(rx[IP].proto, 0x2F)  # GRE encap
+            self.assertEqual(rx[GRE].proto, 0x0800)  # IPv4
+            inner = rx[GRE].payload
+            self.assertNotEqual(rx[IP].len - 20 - 4, len(inner))
+            self.assertEqual(inner[IP].src, self.pg2.remote_ip4)
+            self.assertEqual(inner[IP].dst, "172.16.10.3")
+            self.assert_ip_checksum_valid(inner)
+            payload_len = inner[IP].len - 20 - 20
+            self.assertEqual(payload_len, 65200)
+            # truncated packet to MTU size
+            self.assertNotEqual(payload_len, len(inner[Raw]))
+
+        self.ip4_via_gre4_tunnel.remove_vpp_config()
+        self.gre4.remove_vpp_config()
+
+        self.gre6.add_vpp_config()
+        self.gre6.admin_up()
+        self.gre6.config_ip4()
+
+        #
+        # Add a route that resolves the tunnel's destination
+        # Add IPv6 routes via tunnel interface
+        #
+        self.vapi.feature_gso_enable_disable(
+            sw_if_index=self.gre6.sw_if_index, enable_disable=1
+        )
+        self.ip6_via_gre6_tunnel = VppIpRoute(
+            self,
+            "fd01:10::",
+            64,
+            [
+                VppRoutePath(
+                    "::",
+                    self.gre6.sw_if_index,
+                    proto=FibPathProto.FIB_PATH_NH_PROTO_IP6,
+                )
+            ],
+        )
+        self.ip6_via_gre6_tunnel.add_vpp_config()
+
+        #
+        # Create IPv6 packet
+        #
+        pgre6 = (
+            Ether(src=self.pg2.remote_mac, dst="02:fe:60:1e:a2:79")
+            / IPv6(src=self.pg2.remote_ip6, dst="fd01:10::3")
+            / TCP(sport=1234, dport=1234)
+            / Raw(b"\xa5" * 65200)
+        )
+
+        # test when GSO segmentation is enabled, payload will be segmented
+        # into GSO size (i.e. 1448)
+        rxs = self.send_and_expect(self.pg2, 5 * [pgre6], self.pg0, 225)
+        size = 0
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg0.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg0.remote_mac)
+            self.assertEqual(rx[IPv6].src, self.pg0.local_ip6)
+            self.assertEqual(rx[IPv6].dst, self.pg0.remote_ip6)
+            self.assertEqual(ipv6nh[rx[IPv6].nh], "GRE")
+            self.assertEqual(rx[GRE].proto, 0x86DD)  # IPv6
+            inner = rx[GRE].payload
+            self.assertEqual(rx[IPv6].plen - 4, len(inner))
+            self.assertEqual(inner[IPv6].src, self.pg2.remote_ip6)
+            self.assertEqual(inner[IPv6].dst, "fd01:10::3")
+            self.assert_tcp_checksum_valid(inner)
+            payload_len = inner[IPv6].plen - 20
+            self.assertEqual(payload_len, len(inner[Raw]))
+            size += payload_len
+        self.assertEqual(size, 65200 * 5)
+
+        # disable GSO segmentation
+        self.vapi.feature_gso_enable_disable(
+            sw_if_index=self.gre6.sw_if_index, enable_disable=0
+        )
+
+        # test again, this time packets will be truncated
+        rxs = self.send_and_expect(self.pg2, 5 * [pgre6], self.pg0, 5)
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg0.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg0.remote_mac)
+            self.assertEqual(rx[IPv6].src, self.pg0.local_ip6)
+            self.assertEqual(rx[IPv6].dst, self.pg0.remote_ip6)
+            self.assertEqual(ipv6nh[rx[IPv6].nh], "GRE")
+            self.assertEqual(rx[GRE].proto, 0x86DD)  # IPv6
+            inner = rx[GRE].payload
+            self.assertNotEqual(rx[IPv6].plen - 4, len(inner))
+            self.assertEqual(inner[IPv6].src, self.pg2.remote_ip6)
+            self.assertEqual(inner[IPv6].dst, "fd01:10::3")
+            payload_len = inner[IPv6].plen - 20
+            self.assertEqual(payload_len, 65200)
+            # packets are truncated to MTU size
+            self.assertNotEqual(payload_len, len(inner[Raw]))
+
+        self.ip6_via_gre6_tunnel.remove_vpp_config()
+        self.gre6.remove_vpp_config()
+
     def test_gso_ipsec(self):
         """GSO IPSEC test"""
         #