diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index a322d8b..c5ac8a5 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -1683,7 +1683,7 @@ tx_vlan_set(portid_t port_id, uint16_t vlan_id)
 		return;
 	if (vlan_id_is_invalid(vlan_id))
 		return;
-	ports[port_id].tx_ol_flags |= PKT_TX_VLAN_PKT;
+	ports[port_id].tx_ol_flags |= TESTPMD_TX_OFFLOAD_INSERT_VLAN;
 	ports[port_id].tx_vlan_id = vlan_id;
 }
 
@@ -1692,7 +1692,7 @@ tx_vlan_reset(portid_t port_id)
 {
 	if (port_id_is_invalid(port_id))
 		return;
-	ports[port_id].tx_ol_flags &= ~PKT_TX_VLAN_PKT;
+	ports[port_id].tx_ol_flags &= ~TESTPMD_TX_OFFLOAD_INSERT_VLAN;
 }
 
 void
diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
index 8d10bfd..743094a 100644
--- a/app/test-pmd/csumonly.c
+++ b/app/test-pmd/csumonly.c
@@ -322,7 +322,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 			/* Do not delete, this is required by HW*/
 			ipv4_hdr->hdr_checksum = 0;
 
-			if (tx_ol_flags & 0x1) {
+			if (tx_ol_flags & TESTPMD_TX_OFFLOAD_IP_CKSUM) {
 				/* HW checksum */
 				ol_flags |= PKT_TX_IP_CKSUM;
 			}
@@ -336,7 +336,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 			if (l4_proto == IPPROTO_UDP) {
 				udp_hdr = (struct udp_hdr*) (rte_pktmbuf_mtod(mb,
 						unsigned char *) + l2_len + l3_len);
-				if (tx_ol_flags & 0x2) {
+				if (tx_ol_flags & TESTPMD_TX_OFFLOAD_UDP_CKSUM) {
 					/* HW Offload */
 					ol_flags |= PKT_TX_UDP_CKSUM;
 					if (ipv4_tunnel)
@@ -358,7 +358,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 					uint16_t len;
 
 					/* Check if inner L3/L4 checkum flag is set */
-					if (tx_ol_flags & 0xF0)
+					if (tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_CKSUM_MASK)
 						ol_flags |= PKT_TX_VXLAN_CKSUM;
 
 					inner_l2_len  = sizeof(struct ether_hdr);
@@ -381,7 +381,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 								unsigned char *) + len);
 						inner_l4_proto = inner_ipv4_hdr->next_proto_id;
 
-						if (tx_ol_flags & 0x10) {
+						if (tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_IP_CKSUM) {
 
 							/* Do not delete, this is required by HW*/
 							inner_ipv4_hdr->hdr_checksum = 0;
@@ -394,7 +394,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 								unsigned char *) + len);
 						inner_l4_proto = inner_ipv6_hdr->proto;
 					}
-					if ((inner_l4_proto == IPPROTO_UDP) && (tx_ol_flags & 0x20)) {
+					if ((inner_l4_proto == IPPROTO_UDP) &&
+						(tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_UDP_CKSUM)) {
 
 						/* HW Offload */
 						ol_flags |= PKT_TX_UDP_CKSUM;
@@ -405,7 +406,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 						else if (eth_type == ETHER_TYPE_IPv6)
 							inner_udp_hdr->dgram_cksum = get_ipv6_psd_sum(inner_ipv6_hdr);
 
-					} else if ((inner_l4_proto == IPPROTO_TCP) && (tx_ol_flags & 0x40)) {
+					} else if ((inner_l4_proto == IPPROTO_TCP) &&
+						(tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_TCP_CKSUM)) {
 						/* HW Offload */
 						ol_flags |= PKT_TX_TCP_CKSUM;
 						inner_tcp_hdr = (struct tcp_hdr *) (rte_pktmbuf_mtod(mb,
@@ -414,7 +416,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 							inner_tcp_hdr->cksum = get_ipv4_psd_sum(inner_ipv4_hdr);
 						else if (eth_type == ETHER_TYPE_IPv6)
 							inner_tcp_hdr->cksum = get_ipv6_psd_sum(inner_ipv6_hdr);
-					} else if ((inner_l4_proto == IPPROTO_SCTP) && (tx_ol_flags & 0x80)) {
+					} else if ((inner_l4_proto == IPPROTO_SCTP) &&
+						(tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_SCTP_CKSUM)) {
 						/* HW Offload */
 						ol_flags |= PKT_TX_SCTP_CKSUM;
 						inner_sctp_hdr = (struct sctp_hdr *) (rte_pktmbuf_mtod(mb,
@@ -427,7 +430,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 			} else if (l4_proto == IPPROTO_TCP) {
 				tcp_hdr = (struct tcp_hdr*) (rte_pktmbuf_mtod(mb,
 						unsigned char *) + l2_len + l3_len);
-				if (tx_ol_flags & 0x4) {
+				if (tx_ol_flags & TESTPMD_TX_OFFLOAD_TCP_CKSUM) {
 					ol_flags |= PKT_TX_TCP_CKSUM;
 					tcp_hdr->cksum = get_ipv4_psd_sum(ipv4_hdr);
 				}
@@ -440,7 +443,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 				sctp_hdr = (struct sctp_hdr*) (rte_pktmbuf_mtod(mb,
 						unsigned char *) + l2_len + l3_len);
 
-				if (tx_ol_flags & 0x8) {
+				if (tx_ol_flags & TESTPMD_TX_OFFLOAD_SCTP_CKSUM) {
 					ol_flags |= PKT_TX_SCTP_CKSUM;
 					sctp_hdr->cksum = 0;
 
@@ -465,7 +468,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 			if (l4_proto == IPPROTO_UDP) {
 				udp_hdr = (struct udp_hdr*) (rte_pktmbuf_mtod(mb,
 						unsigned char *) + l2_len + l3_len);
-				if (tx_ol_flags & 0x2) {
+				if (tx_ol_flags & TESTPMD_TX_OFFLOAD_UDP_CKSUM) {
 					/* HW Offload */
 					ol_flags |= PKT_TX_UDP_CKSUM;
 					if (ipv6_tunnel)
@@ -487,7 +490,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 					uint16_t len;
 
 					/* Check if inner L3/L4 checksum flag is set */
-					if (tx_ol_flags & 0xF0)
+					if (tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_CKSUM_MASK)
 						ol_flags |= PKT_TX_VXLAN_CKSUM;
 
 					inner_l2_len  = sizeof(struct ether_hdr);
@@ -511,7 +514,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 						inner_l4_proto = inner_ipv4_hdr->next_proto_id;
 
 						/* HW offload */
-						if (tx_ol_flags & 0x10) {
+						if (tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_IP_CKSUM) {
 
 							/* Do not delete, this is required by HW*/
 							inner_ipv4_hdr->hdr_checksum = 0;
@@ -524,7 +527,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 						inner_l4_proto = inner_ipv6_hdr->proto;
 					}
 
-					if ((inner_l4_proto == IPPROTO_UDP) && (tx_ol_flags & 0x20)) {
+					if ((inner_l4_proto == IPPROTO_UDP) &&
+						(tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_UDP_CKSUM)) {
 						inner_udp_hdr = (struct udp_hdr *) (rte_pktmbuf_mtod(mb,
 							unsigned char *) + len + inner_l3_len);
 						/* HW offload */
@@ -534,7 +538,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 							inner_udp_hdr->dgram_cksum = get_ipv4_psd_sum(inner_ipv4_hdr);
 						else if (eth_type == ETHER_TYPE_IPv6)
 							inner_udp_hdr->dgram_cksum = get_ipv6_psd_sum(inner_ipv6_hdr);
-					} else if ((inner_l4_proto == IPPROTO_TCP) && (tx_ol_flags & 0x40)) {
+					} else if ((inner_l4_proto == IPPROTO_TCP) &&
+						(tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_TCP_CKSUM)) {
 						/* HW offload */
 						ol_flags |= PKT_TX_TCP_CKSUM;
 						inner_tcp_hdr = (struct tcp_hdr *) (rte_pktmbuf_mtod(mb,
@@ -545,7 +550,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 						else if (eth_type == ETHER_TYPE_IPv6)
 							inner_tcp_hdr->cksum = get_ipv6_psd_sum(inner_ipv6_hdr);
 
-					} else if ((inner_l4_proto == IPPROTO_SCTP) && (tx_ol_flags & 0x80)) {
+					} else if ((inner_l4_proto == IPPROTO_SCTP) &&
+						(tx_ol_flags & TESTPMD_TX_OFFLOAD_INNER_SCTP_CKSUM)) {
 						/* HW offload */
 						ol_flags |= PKT_TX_SCTP_CKSUM;
 						inner_sctp_hdr = (struct sctp_hdr *) (rte_pktmbuf_mtod(mb,
@@ -559,7 +565,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 			else if (l4_proto == IPPROTO_TCP) {
 				tcp_hdr = (struct tcp_hdr*) (rte_pktmbuf_mtod(mb,
 						unsigned char *) + l2_len + l3_len);
-				if (tx_ol_flags & 0x4) {
+				if (tx_ol_flags & TESTPMD_TX_OFFLOAD_TCP_CKSUM) {
 					ol_flags |= PKT_TX_TCP_CKSUM;
 					tcp_hdr->cksum = get_ipv6_psd_sum(ipv6_hdr);
 				}
@@ -573,7 +579,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 				sctp_hdr = (struct sctp_hdr*) (rte_pktmbuf_mtod(mb,
 						unsigned char *) + l2_len + l3_len);
 
-				if (tx_ol_flags & 0x8) {
+				if (tx_ol_flags & TESTPMD_TX_OFFLOAD_SCTP_CKSUM) {
 					ol_flags |= PKT_TX_SCTP_CKSUM;
 					sctp_hdr->cksum = 0;
 					/* Sanity check, only number of 4 bytes supported by HW */
diff --git a/app/test-pmd/macfwd.c b/app/test-pmd/macfwd.c
index 38bae23..aa3d705 100644
--- a/app/test-pmd/macfwd.c
+++ b/app/test-pmd/macfwd.c
@@ -85,6 +85,7 @@ pkt_burst_mac_forward(struct fwd_stream *fs)
 	uint16_t nb_rx;
 	uint16_t nb_tx;
 	uint16_t i;
+	uint64_t ol_flags = 0;
 #ifdef RTE_TEST_PMD_RECORD_CORE_CYCLES
 	uint64_t start_tsc;
 	uint64_t end_tsc;
@@ -108,6 +109,8 @@ pkt_burst_mac_forward(struct fwd_stream *fs)
 #endif
 	fs->rx_packets += nb_rx;
 	txp = &ports[fs->tx_port];
+	if (txp->tx_ol_flags & TESTPMD_TX_OFFLOAD_INSERT_VLAN)
+		ol_flags = PKT_TX_VLAN_PKT;
 	for (i = 0; i < nb_rx; i++) {
 		mb = pkts_burst[i];
 		eth_hdr = rte_pktmbuf_mtod(mb, struct ether_hdr *);
@@ -115,7 +118,7 @@ pkt_burst_mac_forward(struct fwd_stream *fs)
 				&eth_hdr->d_addr);
 		ether_addr_copy(&ports[fs->tx_port].eth_addr,
 				&eth_hdr->s_addr);
-		mb->ol_flags = txp->tx_ol_flags;
+		mb->ol_flags = ol_flags;
 		mb->l2_len = sizeof(struct ether_hdr);
 		mb->l3_len = sizeof(struct ipv4_hdr);
 		mb->vlan_tci = txp->tx_vlan_id;
diff --git a/app/test-pmd/macswap.c b/app/test-pmd/macswap.c
index 1786095..ec61657 100644
--- a/app/test-pmd/macswap.c
+++ b/app/test-pmd/macswap.c
@@ -85,6 +85,7 @@ pkt_burst_mac_swap(struct fwd_stream *fs)
 	uint16_t nb_rx;
 	uint16_t nb_tx;
 	uint16_t i;
+	uint64_t ol_flags = 0;
 #ifdef RTE_TEST_PMD_RECORD_CORE_CYCLES
 	uint64_t start_tsc;
 	uint64_t end_tsc;
@@ -108,6 +109,8 @@ pkt_burst_mac_swap(struct fwd_stream *fs)
 #endif
 	fs->rx_packets += nb_rx;
 	txp = &ports[fs->tx_port];
+	if (txp->tx_ol_flags & TESTPMD_TX_OFFLOAD_INSERT_VLAN)
+		ol_flags = PKT_TX_VLAN_PKT;
 	for (i = 0; i < nb_rx; i++) {
 		mb = pkts_burst[i];
 		eth_hdr = rte_pktmbuf_mtod(mb, struct ether_hdr *);
@@ -117,7 +120,7 @@ pkt_burst_mac_swap(struct fwd_stream *fs)
 		ether_addr_copy(&eth_hdr->s_addr, &eth_hdr->d_addr);
 		ether_addr_copy(&addr, &eth_hdr->s_addr);
 
-		mb->ol_flags = txp->tx_ol_flags;
+		mb->ol_flags = ol_flags;
 		mb->l2_len = sizeof(struct ether_hdr);
 		mb->l3_len = sizeof(struct ipv4_hdr);
 		mb->vlan_tci = txp->tx_vlan_id;
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index 9371ba1..d8847cb 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -123,14 +123,28 @@ struct fwd_stream {
 #endif
 };
 
+/** Offload IP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_IP_CKSUM          0x0001
+/** Offload UDP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_UDP_CKSUM         0x0002
+/** Offload TCP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_TCP_CKSUM         0x0004
+/** Offload SCTP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_SCTP_CKSUM        0x0008
+/** Offload inner IP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_INNER_IP_CKSUM    0x0010
+/** Offload inner UDP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_INNER_UDP_CKSUM   0x0020
+/** Offload inner TCP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_INNER_TCP_CKSUM   0x0040
+/** Offload inner SCTP checksum in csum forward engine */
+#define TESTPMD_TX_OFFLOAD_INNER_SCTP_CKSUM  0x0080
+/** Offload inner IP checksum mask */
+#define TESTPMD_TX_OFFLOAD_INNER_CKSUM_MASK  0x00F0
+/** Insert VLAN header in forward engine */
+#define TESTPMD_TX_OFFLOAD_INSERT_VLAN       0x0100
 /**
  * The data structure associated with each port.
- * tx_ol_flags is slightly different from ol_flags of rte_mbuf.
- *   Bit  0: Insert IP checksum
- *   Bit  1: Insert UDP checksum
- *   Bit  2: Insert TCP checksum
- *   Bit  3: Insert SCTP checksum
- *   Bit 11: Insert VLAN Label
  */
 struct rte_port {
 	struct rte_eth_dev_info dev_info;   /**< PCI info + driver name */
@@ -141,7 +155,7 @@ struct rte_port {
 	struct fwd_stream       *rx_stream; /**< Port RX stream, if unique */
 	struct fwd_stream       *tx_stream; /**< Port TX stream, if unique */
 	unsigned int            socket_id;  /**< For NUMA support */
-	uint64_t                tx_ol_flags;/**< Offload Flags of TX packets. */
+	uint16_t                tx_ol_flags;/**< TX Offload Flags (TESTPMD_TX_OFFLOAD...). */
 	uint16_t                tx_vlan_id; /**< Tag Id. in TX VLAN packets. */
 	void                    *fwd_ctx;   /**< Forwarding mode context */
 	uint64_t                rx_bad_ip_csum; /**< rx pkts with bad ip checksum  */
diff --git a/app/test-pmd/txonly.c b/app/test-pmd/txonly.c
index 3d08005..c984670 100644
--- a/app/test-pmd/txonly.c
+++ b/app/test-pmd/txonly.c
@@ -196,6 +196,7 @@ static void
 pkt_burst_transmit(struct fwd_stream *fs)
 {
 	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
+	struct rte_port *txp;
 	struct rte_mbuf *pkt;
 	struct rte_mbuf *pkt_seg;
 	struct rte_mempool *mbp;
@@ -203,7 +204,7 @@ pkt_burst_transmit(struct fwd_stream *fs)
 	uint16_t nb_tx;
 	uint16_t nb_pkt;
 	uint16_t vlan_tci;
-	uint64_t ol_flags;
+	uint64_t ol_flags = 0;
 	uint8_t  i;
 #ifdef RTE_TEST_PMD_RECORD_CORE_CYCLES
 	uint64_t start_tsc;
@@ -216,8 +217,10 @@ pkt_burst_transmit(struct fwd_stream *fs)
 #endif
 
 	mbp = current_fwd_lcore()->mbp;
-	vlan_tci = ports[fs->tx_port].tx_vlan_id;
-	ol_flags = ports[fs->tx_port].tx_ol_flags;
+	txp = &ports[fs->tx_port];
+	vlan_tci = txp->tx_vlan_id;
+	if (txp->tx_ol_flags & TESTPMD_TX_OFFLOAD_INSERT_VLAN)
+		ol_flags = PKT_TX_VLAN_PKT;
 	for (nb_pkt = 0; nb_pkt < nb_pkt_per_burst; nb_pkt++) {
 		pkt = tx_mbuf_alloc(mbp);
 		if (pkt == NULL) {
