diff --git a/datapath/actions.c b/datapath/actions.c
index dcf8591..a1a1241 100644
--- a/datapath/actions.c
+++ b/datapath/actions.c
@@ -738,10 +738,13 @@ err:
 }
 
 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
-		      struct sw_flow_key *key)
+		      uint16_t max_len, struct sw_flow_key *key)
 {
 	struct vport *vport = ovs_vport_rcu(dp, out_port);
 
+	if (unlikely(max_len != 0))
+		OVS_CB(skb)->max_len = max_len;
+
 	if (likely(vport)) {
 		u16 mru = OVS_CB(skb)->mru;
 
@@ -1034,6 +1037,7 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 	 * is slightly obscure just to avoid that.
 	 */
 	int prev_port = -1;
+	uint16_t max_len = 0;
 	const struct nlattr *a;
 	int rem;
 
@@ -1045,9 +1049,10 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
 
 			if (out_skb)
-				do_output(dp, out_skb, prev_port, key);
+				do_output(dp, out_skb, prev_port, max_len, key);
 
 			prev_port = -1;
+			max_len = 0;
 		}
 
 		switch (nla_type(a)) {
@@ -1055,6 +1060,13 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 			prev_port = nla_get_u32(a);
 			break;
 
+        case OVS_ACTION_ATTR_OUTPUT_TRUNC: {
+			struct ovs_action_output_trunc *output_trunc = nla_data(a);
+			prev_port = output_trunc->port;
+			max_len = output_trunc->max_len;
+			break;
+        }
+
 		case OVS_ACTION_ATTR_USERSPACE:
 			output_userspace(dp, skb, key, a, attr, len);
 			break;
@@ -1126,7 +1138,7 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 	}
 
 	if (prev_port != -1)
-		do_output(dp, skb, prev_port, key);
+		do_output(dp, skb, prev_port, max_len, key);
 	else
 		consume_skb(skb);
 
diff --git a/datapath/datapath.h b/datapath/datapath.h
index ceb3372..178d81d 100644
--- a/datapath/datapath.h
+++ b/datapath/datapath.h
@@ -102,6 +102,7 @@ struct datapath {
 struct ovs_skb_cb {
 	struct vport		*input_vport;
 	u16			mru;
+	u16			max_len; /* 0 means original packet size. */
 };
 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 
diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c
index 6ffcc53..4fc4f7b 100644
--- a/datapath/flow_netlink.c
+++ b/datapath/flow_netlink.c
@@ -2170,6 +2170,7 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 		/* Expected argument lengths, (u32)-1 for variable length. */
 		static const u32 action_lens[OVS_ACTION_ATTR_MAX + 1] = {
 			[OVS_ACTION_ATTR_OUTPUT] = sizeof(u32),
+			[OVS_ACTION_ATTR_OUTPUT_TRUNC] = sizeof(struct ovs_action_output_trunc),
 			[OVS_ACTION_ATTR_RECIRC] = sizeof(u32),
 			[OVS_ACTION_ATTR_USERSPACE] = (u32)-1,
 			[OVS_ACTION_ATTR_PUSH_MPLS] = sizeof(struct ovs_action_push_mpls),
@@ -2207,6 +2208,14 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
 				return -EINVAL;
 			break;
 
+		case OVS_ACTION_ATTR_OUTPUT_TRUNC: {
+			const struct ovs_action_output_trunc *output_trunc = nla_data(a);
+			if (output_trunc->port >= DP_MAX_PORTS ||
+					output_trunc->max_len < OVS_ACTION_OUTPUT_MIN)
+				return -EINVAL;
+			break;
+		}
+
 		case OVS_ACTION_ATTR_HASH: {
 			const struct ovs_action_hash *act_hash = nla_data(a);
 
diff --git a/datapath/linux/compat/include/linux/openvswitch.h b/datapath/linux/compat/include/linux/openvswitch.h
index 3b39ebb..4574eb1 100644
--- a/datapath/linux/compat/include/linux/openvswitch.h
+++ b/datapath/linux/compat/include/linux/openvswitch.h
@@ -600,6 +600,13 @@ enum ovs_userspace_attr {
 
 #define OVS_USERSPACE_ATTR_MAX (__OVS_USERSPACE_ATTR_MAX - 1)
 
+struct ovs_action_output_trunc {
+	uint32_t port;
+	uint16_t max_len; /* 0 means original packet size. */
+};
+/* Minimum packet size max_len can have, 60 = ETH_MIN_FRAME_LEN. */
+#define OVS_ACTION_OUTPUT_MIN 60
+
 /**
  * struct ovs_action_push_mpls - %OVS_ACTION_ATTR_PUSH_MPLS action argument.
  * @mpls_lse: MPLS label stack entry to push.
@@ -742,6 +749,7 @@ enum ovs_nat_attr {
  * enum ovs_action_attr - Action types.
  *
  * @OVS_ACTION_ATTR_OUTPUT: Output packet to port.
+ * @OVS_ACTION_ATTR_TRUNC: Output packet to port with truncated packet size.
  * @OVS_ACTION_ATTR_USERSPACE: Send packet to userspace according to nested
  * %OVS_USERSPACE_ATTR_* attributes.
  * @OVS_ACTION_ATTR_PUSH_VLAN: Push a new outermost 802.1Q header onto the
@@ -788,6 +796,7 @@ enum ovs_nat_attr {
 enum ovs_action_attr {
 	OVS_ACTION_ATTR_UNSPEC,
 	OVS_ACTION_ATTR_OUTPUT,	      /* u32 port number. */
+	OVS_ACTION_ATTR_OUTPUT_TRUNC, /* u32 port number + u16 max_len */
 	OVS_ACTION_ATTR_USERSPACE,    /* Nested OVS_USERSPACE_ATTR_*. */
 	OVS_ACTION_ATTR_SET,          /* One nested OVS_KEY_ATTR_*. */
 	OVS_ACTION_ATTR_PUSH_VLAN,    /* struct ovs_action_push_vlan. */
diff --git a/datapath/vport.c b/datapath/vport.c
index 44b9dfb..31a6128 100644
--- a/datapath/vport.c
+++ b/datapath/vport.c
@@ -487,6 +487,8 @@ int ovs_vport_receive(struct vport *vport, struct sk_buff *skb,
 
 	OVS_CB(skb)->input_vport = vport;
 	OVS_CB(skb)->mru = 0;
+	OVS_CB(skb)->max_len = 0;
+
 	if (unlikely(dev_net(skb->dev) != ovs_dp_get_net(vport->dp))) {
 		u32 mark;
 
@@ -615,6 +617,7 @@ static unsigned int packet_length(const struct sk_buff *skb)
 void ovs_vport_send(struct vport *vport, struct sk_buff *skb)
 {
 	int mtu = vport->dev->mtu;
+	u16 max_len = OVS_CB(skb)->max_len;
 
 	if (unlikely(packet_length(skb) > mtu && !skb_is_gso(skb))) {
 		net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
@@ -624,6 +627,9 @@ void ovs_vport_send(struct vport *vport, struct sk_buff *skb)
 		goto drop;
 	}
 
+	if (unlikely(max_len >= OVS_ACTION_OUTPUT_MIN))
+		skb_trim(skb, max_len);
+
 	skb->dev = vport->dev;
 	vport->ops->send(skb);
 	return;
diff --git a/lib/dp-packet.c b/lib/dp-packet.c
index aec7fe7..d32fa85 100644
--- a/lib/dp-packet.c
+++ b/lib/dp-packet.c
@@ -29,6 +29,7 @@ dp_packet_init__(struct dp_packet *b, size_t allocated, enum dp_packet_source so
     b->source = source;
     dp_packet_reset_offsets(b);
     pkt_metadata_init(&b->md, 0);
+    b->max_len = 0;
 }
 
 static void
diff --git a/lib/dp-packet.h b/lib/dp-packet.h
index 000b09d..9f10fa8 100644
--- a/lib/dp-packet.h
+++ b/lib/dp-packet.h
@@ -58,6 +58,7 @@ struct dp_packet {
                                     * or UINT16_MAX. */
     uint16_t l4_ofs;               /* Transport-level header offset,
                                       or UINT16_MAX. */
+    uint16_t max_len;              /* Max packet sent size. 0 means original size. */
     struct pkt_metadata md;
 };
 
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 119dc2d..4b9d559 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -3744,6 +3744,34 @@ dp_execute_cb(void *aux_, struct dp_packet **packets, int cnt,
     int i;
 
     switch ((enum ovs_action_attr)type) {
+    case OVS_ACTION_ATTR_OUTPUT_TRUNC: {
+        struct dp_packet *trunc_pkts[cnt];
+        const struct ovs_action_output_trunc *output_trunc =
+                    nl_attr_get_unspec(a, sizeof *output_trunc);
+
+        p = dp_netdev_lookup_port(dp, output_trunc->port);
+
+        if (output_trunc->max_len >= OVS_ACTION_OUTPUT_MIN) {
+            if (!may_steal) {
+                dp_netdev_clone_pkt_batch(trunc_pkts, packets, cnt);
+                packets = trunc_pkts;
+            }
+            for (i = 0; i < cnt; i++) {
+                packets[i]->max_len = output_trunc->max_len;
+            }
+        }
+
+        if (OVS_LIKELY(p)) {
+            int tx_qid;
+
+            atomic_read_relaxed(&pmd->tx_qid, &tx_qid);
+
+            netdev_send(p->netdev, tx_qid, packets, cnt, may_steal);
+            return;
+        }
+        break;
+    }
+
     case OVS_ACTION_ATTR_OUTPUT:
         p = dp_netdev_lookup_port(dp, u32_to_odp(nl_attr_get_u32(a)));
         if (OVS_LIKELY(p)) {
diff --git a/lib/dpif.c b/lib/dpif.c
index a784de7..272bd24 100644
--- a/lib/dpif.c
+++ b/lib/dpif.c
@@ -1099,6 +1099,7 @@ dpif_execute_helper_cb(void *aux_, struct dp_packet **packets, int cnt,
     switch ((enum ovs_action_attr)type) {
     case OVS_ACTION_ATTR_CT:
     case OVS_ACTION_ATTR_OUTPUT:
+    case OVS_ACTION_ATTR_OUTPUT_TRUNC:
     case OVS_ACTION_ATTR_TUNNEL_PUSH:
     case OVS_ACTION_ATTR_TUNNEL_POP:
     case OVS_ACTION_ATTR_USERSPACE:
diff --git a/lib/netdev.c b/lib/netdev.c
index 3e50694..92201c6 100644
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -758,6 +758,14 @@ netdev_send(struct netdev *netdev, int qid, struct dp_packet **buffers,
         return EOPNOTSUPP;
     }
 
+    for (int i = 0; i < cnt; i++) {
+        struct dp_packet *packet = buffers[i];
+        if (packet->max_len >= OVS_ACTION_OUTPUT_MIN &&
+            packet->max_len < dp_packet_size(packet)) {
+            dp_packet_set_size(packet, packet->max_len);
+        }
+    }
+
     int error = netdev->netdev_class->send(netdev, qid, buffers, cnt,
                                            may_steal);
     if (!error) {
diff --git a/lib/odp-execute.c b/lib/odp-execute.c
index b5204b2..4281334 100644
--- a/lib/odp-execute.c
+++ b/lib/odp-execute.c
@@ -488,6 +488,7 @@ requires_datapath_assistance(const struct nlattr *a)
     switch (type) {
         /* These only make sense in the context of a datapath. */
     case OVS_ACTION_ATTR_OUTPUT:
+    case OVS_ACTION_ATTR_OUTPUT_TRUNC:
     case OVS_ACTION_ATTR_TUNNEL_PUSH:
     case OVS_ACTION_ATTR_TUNNEL_POP:
     case OVS_ACTION_ATTR_USERSPACE:
@@ -624,6 +625,7 @@ odp_execute_actions(void *dp, struct dp_packet **packets, int cnt, bool steal,
             break;
 
         case OVS_ACTION_ATTR_OUTPUT:
+        case OVS_ACTION_ATTR_OUTPUT_TRUNC:
         case OVS_ACTION_ATTR_TUNNEL_PUSH:
         case OVS_ACTION_ATTR_TUNNEL_POP:
         case OVS_ACTION_ATTR_USERSPACE:
diff --git a/lib/odp-util.c b/lib/odp-util.c
index b4689cc..a4b4802 100644
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -107,6 +107,7 @@ odp_action_len(uint16_t type)
 
     switch ((enum ovs_action_attr) type) {
     case OVS_ACTION_ATTR_OUTPUT: return sizeof(uint32_t);
+    case OVS_ACTION_ATTR_OUTPUT_TRUNC: return sizeof(struct ovs_action_output_trunc);
     case OVS_ACTION_ATTR_TUNNEL_PUSH: return ATTR_LEN_VARIABLE;
     case OVS_ACTION_ATTR_TUNNEL_POP: return sizeof(uint32_t);
     case OVS_ACTION_ATTR_USERSPACE: return ATTR_LEN_VARIABLE;
@@ -775,6 +776,14 @@ format_odp_action(struct ds *ds, const struct nlattr *a)
     case OVS_ACTION_ATTR_OUTPUT:
         ds_put_format(ds, "%"PRIu32, nl_attr_get_u32(a));
         break;
+    case OVS_ACTION_ATTR_OUTPUT_TRUNC: {
+        const struct ovs_action_output_trunc *output_trunc =
+                       nl_attr_get_unspec(a, sizeof *output_trunc);
+        ds_put_format(ds, "(port=%"PRIu32",max_len=%"PRIu16")",
+                       output_trunc->port, output_trunc->max_len);
+        break;
+    }
+    break;
     case OVS_ACTION_ATTR_TUNNEL_POP:
         ds_put_format(ds, "tnl_pop(%"PRIu32")", nl_attr_get_u32(a));
         break;
@@ -1516,13 +1525,11 @@ parse_odp_action(const char *s, const struct simap *port_names,
     {
         uint32_t port;
         int n;
-
         if (ovs_scan(s, "%"SCNi32"%n", &port, &n)) {
             nl_msg_put_u32(actions, OVS_ACTION_ATTR_OUTPUT, port);
             return n;
         }
     }
-
     if (port_names) {
         int len = strcspn(s, delimiters);
         struct simap_node *node;
diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
index aac4ff0..9374380 100644
--- a/lib/ofp-actions.c
+++ b/lib/ofp-actions.c
@@ -299,6 +299,9 @@ enum ofp_raw_action_type {
     /* NX1.0+(36): struct nx_action_nat, ... */
     NXAST_RAW_NAT,
 
+    /* NX1.0+(38): struct nx_action_output_trunc. */
+    NXAST_RAW_OUTPUT_TRUNC,
+
 /* ## ------------------ ## */
 /* ## Debugging actions. ## */
 /* ## ------------------ ## */
@@ -379,6 +382,7 @@ ofpact_next_flattened(const struct ofpact *ofpact)
     case OFPACT_CONTROLLER:
     case OFPACT_ENQUEUE:
     case OFPACT_OUTPUT_REG:
+    case OFPACT_OUTPUT_TRUNC:
     case OFPACT_BUNDLE:
     case OFPACT_SET_FIELD:
     case OFPACT_SET_VLAN_VID:
@@ -536,6 +540,36 @@ encode_OUTPUT(const struct ofpact_output *output,
 }
 
 static char * OVS_WARN_UNUSED_RESULT
+parse_truncate_subfield(struct ofpact_output_trunc *output_trunc,
+                        const char *arg_)
+{
+    char *key, *value;
+    char *error = NULL;
+    char *arg = CONST_CAST(char *, arg_);
+
+    while (ofputil_parse_key_value(&arg, &key, &value)) {
+        char *error;
+        if (!strcmp(key, "port")) {
+            if (!ofputil_port_from_string(value, &output_trunc->port)) {
+                return xasprintf("%s: output to unknown port", value);
+            }
+        } else if (!strcmp(key, "max_len")) {
+            error = str_to_u16(value, key, &output_trunc->max_len);
+        } else {
+            error = xasprintf("invalid key '%s' in output_trunc argument",
+                          key);
+        }
+        if (error) {
+            return error;
+        }
+    }
+    if (!error && arg[0]) {
+        error = xstrdup("unexpected input following field syntax");
+    }
+    return error;
+}
+
+static char * OVS_WARN_UNUSED_RESULT
 parse_OUTPUT(const char *arg, struct ofpbuf *ofpacts,
              enum ofputil_protocol *usable_protocols OVS_UNUSED)
 {
@@ -545,6 +579,10 @@ parse_OUTPUT(const char *arg, struct ofpbuf *ofpacts,
         output_reg = ofpact_put_OUTPUT_REG(ofpacts);
         output_reg->max_len = UINT16_MAX;
         return mf_parse_subfield(&output_reg->src, arg);
+    } else if (strstr(arg, "port=") && strstr(arg, "max_len=")) {
+        struct ofpact_output_trunc *output_trunc;
+        output_trunc = ofpact_put_OUTPUT_TRUNC(ofpacts);
+        return parse_truncate_subfield(output_trunc, arg);
     } else {
         struct ofpact_output *output;
 
@@ -5512,6 +5550,62 @@ parse_NAT(char *arg, struct ofpbuf *ofpacts,
     return NULL;
 }
 
+/* Truncate output action. */
+struct nx_action_output_trunc {
+    ovs_be16 type;              /* OFPAT_VENDOR. */
+    ovs_be16 len;               /* At least 16. */
+    ovs_be32 vendor;            /* NX_VENDOR_ID. */
+    ovs_be16 subtype;           /* NXAST_OUTPUT_TRUNC. */
+    ovs_be16 max_len;           /* Truncate packet to size bytes */
+    ovs_be32 port;              /* Output port */
+};
+OFP_ASSERT(sizeof(struct nx_action_output_trunc) == 16);
+
+static enum ofperr
+decode_NXAST_RAW_OUTPUT_TRUNC(const struct nx_action_output_trunc *natrc,
+                            enum ofp_version ofp_version OVS_UNUSED,
+                            struct ofpbuf *out)
+{
+    struct ofpact_output_trunc *output_trunc;
+
+    output_trunc = ofpact_put_OUTPUT_TRUNC(out);
+    output_trunc->max_len = ntohs(natrc->max_len);
+    output_trunc->port = ntohl(natrc->port);
+
+    if (output_trunc->max_len < OVS_ACTION_OUTPUT_MIN) {
+        return OFPERR_OFPBAC_BAD_ARGUMENT;
+    }
+    return 0;
+}
+
+static void
+encode_OUTPUT_TRUNC(const struct ofpact_output_trunc *output_trunc,
+                  enum ofp_version ofp_version OVS_UNUSED,
+                  struct ofpbuf *out)
+{
+    struct nx_action_output_trunc *natrc = put_NXAST_OUTPUT_TRUNC(out);
+
+    natrc->max_len = htons(output_trunc->max_len);
+    natrc->port = htonl(output_trunc->port);
+}
+
+static char * OVS_WARN_UNUSED_RESULT
+parse_OUTPUT_TRUNC(const char *arg OVS_UNUSED, struct ofpbuf *ofpacts OVS_UNUSED,
+                 enum ofputil_protocol *usable_protocols OVS_UNUSED)
+{
+    OVS_NOT_REACHED(); /* output_trunc action uses parse_OUTPUT. */
+    return NULL;
+}
+
+static void
+format_OUTPUT_TRUNC(const struct ofpact_output_trunc *a, struct ds *s)
+{
+    if (ofp_to_u16(a->port) < ofp_to_u16(OFPP_MAX)) {
+         ds_put_format(s, "%soutput%s(port=%"PRIu16",max_len=%"PRIu16")",
+                       colors.special, colors.end, a->port, a->max_len);
+    }
+}
+
 
 /* Meter instruction. */
 
@@ -5906,6 +6000,7 @@ ofpact_is_set_or_move_action(const struct ofpact *a)
     case OFPACT_NOTE:
     case OFPACT_OUTPUT:
     case OFPACT_OUTPUT_REG:
+    case OFPACT_OUTPUT_TRUNC:
     case OFPACT_POP_MPLS:
     case OFPACT_POP_QUEUE:
     case OFPACT_PUSH_MPLS:
@@ -5934,6 +6029,7 @@ ofpact_is_allowed_in_actions_set(const struct ofpact *a)
     case OFPACT_DEC_TTL:
     case OFPACT_GROUP:
     case OFPACT_OUTPUT:
+    case OFPACT_OUTPUT_TRUNC:
     case OFPACT_POP_MPLS:
     case OFPACT_PUSH_MPLS:
     case OFPACT_PUSH_VLAN:
@@ -6157,6 +6253,7 @@ ovs_instruction_type_from_ofpact_type(enum ofpact_type type)
     case OFPACT_CONTROLLER:
     case OFPACT_ENQUEUE:
     case OFPACT_OUTPUT_REG:
+    case OFPACT_OUTPUT_TRUNC:
     case OFPACT_BUNDLE:
     case OFPACT_SET_VLAN_VID:
     case OFPACT_SET_VLAN_PCP:
@@ -6585,6 +6682,10 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
     case OFPACT_OUTPUT_REG:
         return mf_check_src(&ofpact_get_OUTPUT_REG(a)->src, flow);
 
+    case OFPACT_OUTPUT_TRUNC:
+        return ofpact_check_output_port(ofpact_get_OUTPUT_TRUNC(a)->port,
+                                        max_ports);
+
     case OFPACT_BUNDLE:
         return bundle_check(ofpact_get_BUNDLE(a), max_ports, flow);
 
@@ -7261,6 +7362,7 @@ ofpact_outputs_to_port(const struct ofpact *ofpact, ofp_port_t port)
         return port == OFPP_CONTROLLER;
 
     case OFPACT_OUTPUT_REG:
+    case OFPACT_OUTPUT_TRUNC:
     case OFPACT_BUNDLE:
     case OFPACT_SET_VLAN_VID:
     case OFPACT_SET_VLAN_PCP:
diff --git a/lib/ofp-actions.h b/lib/ofp-actions.h
index 4bd8854..2df7841 100644
--- a/lib/ofp-actions.h
+++ b/lib/ofp-actions.h
@@ -108,6 +108,7 @@
     OFPACT(UNROLL_XLATE,    ofpact_unroll_xlate, ofpact, "unroll_xlate") \
     OFPACT(CT,              ofpact_conntrack,   ofpact, "ct")           \
     OFPACT(NAT,             ofpact_nat,         ofpact, "nat")          \
+    OFPACT(OUTPUT_TRUNC,    ofpact_output_trunc,ofpact, "output_trunc") \
                                                                         \
     /* Debugging actions.                                               \
      *                                                                  \
@@ -290,6 +291,15 @@ struct ofpact_output_reg {
     struct mf_subfield src;
 };
 
+/* OFPACT_OUTPUT_TRUNC.
+ *
+ * Used for NXAST_OUTPUT_TRUNC. */
+struct ofpact_output_trunc {
+    struct ofpact ofpact;
+    ofp_port_t port;            /* Output port. */
+    uint16_t max_len;           /* Max send len. */
+};
+
 /* Bundle slave choice algorithm to apply.
  *
  * In the descriptions below, 'slaves' is the list of possible slaves in the
diff --git a/ofproto/ofproto-dpif-sflow.c b/ofproto/ofproto-dpif-sflow.c
index fbc82b7..dde4cc6 100644
--- a/ofproto/ofproto-dpif-sflow.c
+++ b/ofproto/ofproto-dpif-sflow.c
@@ -1105,6 +1105,12 @@ dpif_sflow_read_actions(const struct flow *flow,
 	    sflow_actions->out_port = u32_to_odp(nl_attr_get_u32(a));
 	    break;
 
+    case OVS_ACTION_ATTR_OUTPUT_TRUNC: {
+        const struct ovs_action_output_trunc *output =
+                    nl_attr_get_unspec(a, sizeof *output);
+	    sflow_actions->out_port = u32_to_odp(output->port);
+        break;
+    }
 	case OVS_ACTION_ATTR_TUNNEL_POP:
 	    /* XXX: Do not handle this for now.  It's not clear
 	     * if we should start with encap_depth == 1 when we
diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
index a02dc24..bf3d47a 100644
--- a/ofproto/ofproto-dpif-xlate.c
+++ b/ofproto/ofproto-dpif-xlate.c
@@ -3925,6 +3925,39 @@ xlate_output_reg_action(struct xlate_ctx *ctx,
 }
 
 static void
+xlate_output_trunc_action(struct xlate_ctx *ctx,
+                    ofp_port_t port, uint16_t max_len)
+{
+    odp_port_t odp_port;
+    struct ovs_action_output_trunc *output_trunc;
+
+    switch (port) {
+    case OFPP_IN_PORT:
+    case OFPP_TABLE:
+    case OFPP_NORMAL:
+    case OFPP_FLOOD:
+    case OFPP_ALL:
+    case OFPP_CONTROLLER:
+    case OFPP_NONE:
+    case OFPP_LOCAL:
+        xlate_report(ctx, "output_trunc does not support this port");
+        break;
+    default:
+        if (port != ctx->xin->flow.in_port.ofp_port) {
+            output_trunc = nl_msg_put_unspec_uninit(ctx->odp_actions,
+                                              OVS_ACTION_ATTR_OUTPUT_TRUNC,
+                                              sizeof *output_trunc);
+            odp_port = ofp_port_to_odp_port(ctx->xbridge, port);
+            output_trunc->port = odp_port;
+            output_trunc->max_len = max_len;
+        } else {
+            xlate_report(ctx, "skipping output to input port");
+        }
+        break;
+    }
+}
+
+static void
 xlate_enqueue_action(struct xlate_ctx *ctx,
                      const struct ofpact_enqueue *enqueue)
 {
@@ -4209,6 +4242,7 @@ freeze_unroll_actions(const struct ofpact *a, const struct ofpact *end,
     for (; a < end; a = ofpact_next(a)) {
         switch (a->type) {
         case OFPACT_OUTPUT_REG:
+        case OFPACT_OUTPUT_TRUNC:
         case OFPACT_GROUP:
         case OFPACT_OUTPUT:
         case OFPACT_CONTROLLER:
@@ -4714,6 +4748,11 @@ do_xlate_actions(const struct ofpact *ofpacts, size_t ofpacts_len,
             xlate_output_reg_action(ctx, ofpact_get_OUTPUT_REG(a));
             break;
 
+        case OFPACT_OUTPUT_TRUNC:
+            xlate_output_trunc_action(ctx, ofpact_get_OUTPUT_TRUNC(a)->port,
+                                ofpact_get_OUTPUT_TRUNC(a)->max_len);
+            break;
+
         case OFPACT_LEARN:
             xlate_learn_action(ctx, ofpact_get_LEARN(a));
             break;
diff --git a/tests/ofproto-dpif.at b/tests/ofproto-dpif.at
index da29ac2..6d9197b 100644
--- a/tests/ofproto-dpif.at
+++ b/tests/ofproto-dpif.at
@@ -5309,6 +5309,59 @@ PORTNAME
 	portName=p2
 ])])
 
+AT_SETUP([ofproto-dpif - output_trunc action])
+OVS_VSWITCHD_START
+add_of_ports br0 1 2 3 4 5
+
+AT_CHECK([ovs-vsctl -- set Interface p1 type=dummy options:pcap=p1.pcap])
+AT_CHECK([ovs-vsctl -- set Interface p2 type=dummy options:pstream=punix:p2.sock])
+AT_CHECK([ovs-vsctl -- set Interface p3 type=dummy   options:stream=unix:p2.sock])
+AT_CHECK([ovs-vsctl -- set Interface p4 type=dummy options:pstream=punix:p4.sock])
+AT_CHECK([ovs-vsctl -- set Interface p5 type=dummy   options:stream=unix:p4.sock])
+
+dnl output:2(max_len=32) shows here as truncated size
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=3,actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=5,actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=1,actions=output(port=2,max_len=64),output:4'])
+
+dnl An 170 byte packet
+AT_CHECK([ovs-appctl netdev-dummy/receive p1 '000c29c8a0a4005056c0000808004500009cb4a6000040019003c0a8da01c0a8da640800cb5fa762000556f431ad0009388e08090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f'])
+
+AT_CHECK([ovs-ofctl parse-pcap p1.pcap], [0], [dnl
+icmp,in_port=ANY,vlan_tci=0x0000,dl_src=00:50:56:c0:00:08,dl_dst=00:0c:29:c8:a0:a4,nw_src=192.168.218.1,nw_dst=192.168.218.100,nw_tos=0,nw_ecn=0,nw_ttl=64,icmp_type=8,icmp_code=0
+])
+dnl packet with truncated size
+AT_CHECK([ovs-ofctl dump-flows br0 | grep "in_port=3" | sed -n 's/.*\(n\_bytes=64\).*/\1/p'], [0], [dnl
+n_bytes=64
+])
+dnl dnl packet with original size
+AT_CHECK([ovs-ofctl dump-flows br0 | grep "in_port=5" | sed -n 's/.*\(n\_bytes=170\).*/\1/p'], [0], [dnl
+n_bytes=170
+])
+
+dnl More complicated case
+AT_CHECK([ovs-ofctl del-flows br0])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=3,actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=5,actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=1,actions=output(port=2,max_len=64),output(port=2,  max_len=128),output( port=4,max_len=60 ),output:2,output:4'])
+
+dnl An 170 byte packet
+AT_CHECK([ovs-appctl netdev-dummy/receive p1 '000c29c8a0a4005056c0000808004500009cb4a6000040019003c0a8da01c0a8da640800cb5fa762000556f431ad0009388e08090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f'])
+
+sleep 1
+dnl packet size: 64 + 128 + 170 = 362
+AT_CHECK([ovs-ofctl dump-flows br0 | grep "in_port=3" | sed -n 's/.*\(n\_bytes=362\).*/\1/p'], [0], [dnl
+n_bytes=362
+])
+dnl packet size: 60 + 170 = 230
+AT_CHECK([ovs-ofctl dump-flows br0 | grep "in_port=5" | sed -n 's/.*\(n\_bytes=230\).*/\1/p'], [0], [dnl
+n_bytes=230
+])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP
+
+
 AT_SETUP([ofproto-dpif - sFlow packet sampling - IPv4 collector])
 CHECK_SFLOW_SAMPLING_PACKET([127.0.0.1])
 AT_CLEANUP
diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 28adbdc..cf8d3f3 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -49,6 +49,72 @@ NS_CHECK_EXEC([at_ns0], [ping -s 3200 -q -c 3 -i 0.3 -w 2 10.2.2.2 | FORMAT_PING
 OVS_TRAFFIC_VSWITCHD_STOP
 AT_CLEANUP
 
+AT_SETUP([datapath - output_trunc action])
+OVS_TRAFFIC_VSWITCHD_START()
+
+AT_CHECK([ovs-ofctl del-flows br0])
+
+dnl Create p0 and ovs-p0(1)
+ADD_NAMESPACES(at_ns0)
+ADD_VETH(p0, at_ns0, br0, "10.1.1.1/24")
+NS_CHECK_EXEC([at_ns0], [ip link set dev p0 address e6:66:c1:11:11:11])
+NS_CHECK_EXEC([at_ns0], [arp -s 10.1.1.2 e6:66:c1:22:22:22])
+
+dnl Create p1(3) and ovs-p1(2), packets received from ovs-p1 will appear in p1
+AT_CHECK([ip link add p1 type veth peer name ovs-p1])
+AT_CHECK([ip link set dev ovs-p1 up])
+AT_CHECK([ip link set dev p1 up])
+AT_CHECK([ovs-vsctl add-port br0 ovs-p1 -- set interface ovs-p1 ofport_request=2])
+dnl Use p1 to check the truncated packet
+AT_CHECK([ovs-vsctl add-port br0 p1 -- set interface p1 ofport_request=3])
+
+dnl Create p2(5) and ovs-p2(4)
+AT_CHECK([ip link add p2 type veth peer name ovs-p2])
+AT_CHECK([ip link set dev ovs-p2 up])
+AT_CHECK([ip link set dev p2 up])
+AT_CHECK([ovs-vsctl add-port br0 ovs-p2 -- set interface ovs-p2 ofport_request=4])
+dnl Use p1 to check the truncated packet
+AT_CHECK([ovs-vsctl add-port br0 p2 -- set interface p2 ofport_request=5])
+
+dnl test1: basic
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=3 dl_dst=e6:66:c1:22:22:22 actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=5 dl_dst=e6:66:c1:22:22:22 actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=1 dl_dst=e6:66:c1:22:22:22 actions=output(port=2,max_len=100),output:4'])
+
+NS_CHECK_EXEC([at_ns0], [ping -q -c 1 -s 1024 -w 0 10.1.1.2 | FORMAT_PING], [0], [dnl
+1 packets transmitted, 0 received, 100% packet loss, time 0ms
+])
+AT_CHECK([ovs-ofctl dump-flows br0 table=0 | grep "in_port=3" |  sed -n 's/.*\(n\_bytes=100\).*/\1/p'], [0], [dnl
+n_bytes=100
+])
+dnl packet with original size
+AT_CHECK([ovs-ofctl dump-flows br0 table=0 | grep "in_port=5" | sed -n 's/.*\(n\_bytes=1066\).*/\1/p'], [0], [dnl
+n_bytes=1066
+])
+
+dnl test2: more complicated output actions
+AT_CHECK([ovs-ofctl del-flows br0])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=3 dl_dst=e6:66:c1:22:22:22 actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=5 dl_dst=e6:66:c1:22:22:22 actions=drop'])
+AT_CHECK([ovs-ofctl add-flow br0 'in_port=1 dl_dst=e6:66:c1:22:22:22 actions=output(port=2,max_len=100),output:4,output(port=2,max_len=100),output(port=4,max_len=100),output:2'])
+
+NS_CHECK_EXEC([at_ns0], [ping -q -c 1 -s 1024 -w 0 10.1.1.2 | FORMAT_PING], [0], [dnl
+1 packets transmitted, 0 received, 100% packet loss, time 0ms
+])
+dnl 100 + 100 + 1066 = 1266
+AT_CHECK([ovs-ofctl dump-flows br0 table=0 | grep "in_port=3" |  sed -n 's/.*\(n\_bytes=1266\).*/\1/p'], [0], [dnl
+n_bytes=1266
+])
+dnl 1066 + 100 = 1166
+AT_CHECK([ovs-ofctl dump-flows br0 table=0 | grep "in_port=5" | sed -n 's/.*\(n\_bytes=1166\).*/\1/p'], [0], [dnl
+n_bytes=1166
+])
+
+OVS_TRAFFIC_VSWITCHD_STOP
+AT_CHECK([ip link del ovs-p1])
+AT_CHECK([ip link del ovs-p2])
+AT_CLEANUP
+
 AT_SETUP([datapath - ping6 between two ports])
 OVS_TRAFFIC_VSWITCHD_START()
 
