diff --git a/app/test-pmd/flowgen.c b/app/test-pmd/flowgen.c
index 3bf6e1ce97..5b389165bc 100644
--- a/app/test-pmd/flowgen.c
+++ b/app/test-pmd/flowgen.c
@@ -40,41 +40,37 @@
 
 #include "testpmd.h"
 
-/* hardcoded configuration (for now) */
-static unsigned cfg_n_flows	= 1024;
-static uint32_t cfg_ip_src	= RTE_IPV4(10, 254, 0, 0);
-static uint32_t cfg_ip_dst	= RTE_IPV4(10, 253, 0, 0);
-static uint16_t cfg_udp_src	= 1000;
-static uint16_t cfg_udp_dst	= 1001;
+/*
+ * Hardcoded range for flow generation.
+ *
+ * Total number of flows =
+ *     cfg_n_ip_src * cfg_n_ip_dst * cfg_n_udp_src * cfg_n_udp_dst
+ */
+static uint32_t cfg_n_ip_src = 100;
+static uint32_t cfg_n_ip_dst = 100;
+static uint32_t cfg_n_udp_src = 10;
+static uint32_t cfg_n_udp_dst = 10;
+
+/* Base ip and port for flow generation. */
+static uint32_t cfg_ip_src_base = RTE_IPV4(10, 254, 0, 0);
+static uint32_t cfg_ip_dst_base = RTE_IPV4(10, 253, 0, 0);
+static uint16_t cfg_udp_src_base = 1000;
+static uint16_t cfg_udp_dst_base = 1001;
 static struct rte_ether_addr cfg_ether_src =
 	{{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x00 }};
 static struct rte_ether_addr cfg_ether_dst =
 	{{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x01 }};
 
+RTE_DEFINE_PER_LCORE(uint32_t, _next_ip_src);
+RTE_DEFINE_PER_LCORE(uint32_t, _next_ip_dst);
+RTE_DEFINE_PER_LCORE(uint32_t, _next_udp_src);
+RTE_DEFINE_PER_LCORE(uint32_t, _next_udp_dst);
+
 #define IP_DEFTTL  64   /* from RFC 1340. */
 
 /* Use this type to inform GCC that ip_sum violates aliasing rules. */
 typedef unaligned_uint16_t alias_int16_t __attribute__((__may_alias__));
 
-static inline uint16_t
-ip_sum(const alias_int16_t *hdr, int hdr_len)
-{
-	uint32_t sum = 0;
-
-	while (hdr_len > 1)
-	{
-		sum += *hdr++;
-		if (sum & 0x80000000)
-			sum = (sum & 0xFFFF) + (sum >> 16);
-		hdr_len -= 2;
-	}
-
-	while (sum >> 16)
-		sum = (sum & 0xFFFF) + (sum >> 16);
-
-	return ~sum;
-}
-
 /*
  * Multi-flow generation mode.
  *
@@ -85,7 +81,7 @@ ip_sum(const alias_int16_t *hdr, int hdr_len)
 static void
 pkt_burst_flow_gen(struct fwd_stream *fs)
 {
-	unsigned pkt_size = tx_pkt_length - 4;	/* Adjust FCS */
+	uint32_t pkt_size = tx_pkt_length - 4; /* Adjust FCS */
 	struct rte_mbuf  *pkts_burst[MAX_PKT_BURST];
 	struct rte_mempool *mbp;
 	struct rte_mbuf  *pkt = NULL;
@@ -102,15 +98,18 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
 	uint32_t retry;
 	uint64_t tx_offloads;
 	uint64_t start_tsc = 0;
-	static int next_flow = 0;
+	uint32_t next_ip_src = RTE_PER_LCORE(_next_ip_src);
+	uint32_t next_ip_dst = RTE_PER_LCORE(_next_ip_dst);
+	uint32_t next_udp_src = RTE_PER_LCORE(_next_udp_src);
+	uint32_t next_udp_dst = RTE_PER_LCORE(_next_udp_dst);
 
 	get_start_cycles(&start_tsc);
 
 	/* Receive a burst of packets and discard them. */
 	nb_rx = rte_eth_rx_burst(fs->rx_port, fs->rx_queue, pkts_burst,
 				 nb_pkt_per_burst);
+	inc_rx_burst_stats(fs, nb_rx);
 	fs->rx_packets += nb_rx;
-
 	for (i = 0; i < nb_rx; i++)
 		rte_pktmbuf_free(pkts_burst[i]);
 
@@ -144,7 +143,8 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
 			eth_hdr = rte_pktmbuf_mtod(pkt, struct rte_ether_hdr *);
 			rte_ether_addr_copy(&cfg_ether_dst, &eth_hdr->d_addr);
 			rte_ether_addr_copy(&cfg_ether_src, &eth_hdr->s_addr);
-			eth_hdr->ether_type = rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4);
+			eth_hdr->ether_type =
+				rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4);
 
 			/* Initialize IP header. */
 			ip_hdr = (struct rte_ipv4_hdr *)(eth_hdr + 1);
@@ -155,22 +155,30 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
 			ip_hdr->time_to_live	= IP_DEFTTL;
 			ip_hdr->next_proto_id	= IPPROTO_UDP;
 			ip_hdr->packet_id	= 0;
-			ip_hdr->src_addr	= rte_cpu_to_be_32(cfg_ip_src);
-			ip_hdr->dst_addr	= rte_cpu_to_be_32(cfg_ip_dst +
-								   next_flow);
-			ip_hdr->total_length	= RTE_CPU_TO_BE_16(pkt_size -
-								   sizeof(*eth_hdr));
-			ip_hdr->hdr_checksum	= ip_sum((const alias_int16_t *)ip_hdr,
-							 sizeof(*ip_hdr));
+			ip_hdr->src_addr	=
+				rte_cpu_to_be_32(cfg_ip_src_base
+						+ next_ip_src);
+			ip_hdr->dst_addr	=
+				rte_cpu_to_be_32(cfg_ip_dst_base
+						+ next_ip_dst);
+			ip_hdr->total_length	=
+				RTE_CPU_TO_BE_16(pkt_size
+						- sizeof(*eth_hdr));
+			rte_ipv4_cksum(ip_hdr);
 
 			/* Initialize UDP header. */
 			udp_hdr = (struct rte_udp_hdr *)(ip_hdr + 1);
-			udp_hdr->src_port	= rte_cpu_to_be_16(cfg_udp_src);
-			udp_hdr->dst_port	= rte_cpu_to_be_16(cfg_udp_dst);
+			udp_hdr->src_port	=
+				rte_cpu_to_be_16(cfg_udp_src_base
+						+ next_udp_src);
+			udp_hdr->dst_port	=
+				rte_cpu_to_be_16(cfg_udp_dst_base
+						+ next_udp_dst);
+			udp_hdr->dgram_len	=
+				RTE_CPU_TO_BE_16(pkt_size
+						- sizeof(*eth_hdr)
+						- sizeof(*ip_hdr));
 			udp_hdr->dgram_cksum	= 0; /* No UDP checksum. */
-			udp_hdr->dgram_len	= RTE_CPU_TO_BE_16(pkt_size -
-								   sizeof(*eth_hdr) -
-								   sizeof(*ip_hdr));
 			pkt->nb_segs		= 1;
 			pkt->pkt_len		= pkt_size;
 			pkt->ol_flags		&= EXT_ATTACHED_MBUF;
@@ -185,30 +193,57 @@ pkt_burst_flow_gen(struct fwd_stream *fs)
 		}
 		pkts_burst[nb_pkt] = pkt;
 
-		next_flow = (next_flow + 1) % cfg_n_flows;
+		if (++next_udp_dst < cfg_n_udp_dst)
+			continue;
+		next_udp_dst = 0;
+		if (++next_udp_src < cfg_n_udp_src)
+			continue;
+		next_udp_src = 0;
+		if (++next_ip_dst < cfg_n_ip_dst)
+			continue;
+		next_ip_dst = 0;
+		if (++next_ip_src < cfg_n_ip_src)
+			continue;
+		next_ip_src = 0;
 	}
 
 	nb_tx = rte_eth_tx_burst(fs->tx_port, fs->tx_queue, pkts_burst, nb_pkt);
 	/*
 	 * Retry if necessary
 	 */
-	if (unlikely(nb_tx < nb_rx) && fs->retry_enabled) {
+	if (unlikely(nb_tx < nb_pkt) && fs->retry_enabled) {
 		retry = 0;
-		while (nb_tx < nb_rx && retry++ < burst_tx_retry_num) {
+		while (nb_tx < nb_pkt && retry++ < burst_tx_retry_num) {
 			rte_delay_us(burst_tx_delay_time);
 			nb_tx += rte_eth_tx_burst(fs->tx_port, fs->tx_queue,
-					&pkts_burst[nb_tx], nb_rx - nb_tx);
+					&pkts_burst[nb_tx], nb_pkt - nb_tx);
 		}
 	}
-	fs->tx_packets += nb_tx;
 
 	inc_tx_burst_stats(fs, nb_tx);
-	if (unlikely(nb_tx < nb_pkt)) {
-		/* Back out the flow counter. */
-		next_flow -= (nb_pkt - nb_tx);
-		while (next_flow < 0)
-			next_flow += cfg_n_flows;
+	fs->tx_packets += nb_tx;
+	/* Catch up flow idx by actual sent. */
+	for (i = 0; i < nb_tx; ++i) {
+		RTE_PER_LCORE(_next_udp_dst) = RTE_PER_LCORE(_next_udp_dst) + 1;
+		if (RTE_PER_LCORE(_next_udp_dst) < cfg_n_udp_dst)
+			continue;
+		RTE_PER_LCORE(_next_udp_dst) = 0;
+		RTE_PER_LCORE(_next_udp_src) = RTE_PER_LCORE(_next_udp_src) + 1;
+		if (RTE_PER_LCORE(_next_udp_src) < cfg_n_udp_src)
+			continue;
+		RTE_PER_LCORE(_next_udp_src) = 0;
+		RTE_PER_LCORE(_next_ip_dst) = RTE_PER_LCORE(_next_ip_dst) + 1;
+		if (RTE_PER_LCORE(_next_ip_dst) < cfg_n_ip_dst)
+			continue;
+		RTE_PER_LCORE(_next_ip_dst) = 0;
+		RTE_PER_LCORE(_next_ip_src) = RTE_PER_LCORE(_next_ip_src) + 1;
+		if (RTE_PER_LCORE(_next_ip_src) < cfg_n_ip_src)
+			continue;
+		RTE_PER_LCORE(_next_ip_src) = 0;
+	}
 
+	if (unlikely(nb_tx < nb_pkt)) {
+		fs->fwd_dropped += nb_pkt - nb_tx;
 		do {
 			rte_pktmbuf_free(pkts_burst[nb_tx]);
 		} while (++nb_tx < nb_pkt);
