diff --git a/pinger b/pinger
index 5703e71..57d563d 100755
Binary files a/pinger and b/pinger differ
diff --git a/pinger.go b/pinger.go
index 83b15ad..903556f 100644
--- a/pinger.go
+++ b/pinger.go
@@ -34,20 +34,16 @@ var PayloadSize uint
 func main() {
 
 	flag.IntVar(&PingCount, "count", 5, "Number of Ping packets to send.")
-
 	flag.StringVar(&NIC, "interface", "ens9", "Network interface to attach to.")
 	flag.IntVar(&QueueID, "queue", 0, "The queue on the network interface to attach to.")
 	flag.StringVar(&SrcMAC, "srcmac", "b2968175b211", "Source MAC address to use in sent frames.")
 	flag.StringVar(&DstMAC, "dstmac", "ffffffffffff", "Destination MAC address to use in sent frames.")
 	flag.StringVar(&SrcIP, "srcip", "192.168.111.10", "Source IP address to use in sent frames.")
 	flag.StringVar(&DstIP, "dstip", "192.168.111.1", "Destination IP address to use in sent frames.")
-	flag.UintVar(&SrcPort, "srcport", 1234, "Source UDP port.")
-	flag.UintVar(&DstPort, "dstport", 1234, "Destination UDP port.")
-	flag.UintVar(&PayloadSize, "payloadsize", 10, "Size of the UDP payload.")
+	flag.UintVar(&PayloadSize, "payloadsize", 10, "Size of the payload.")
 	flag.Parse()
 
 	// Initialize the XDP socket.
-
 	link, err := netlink.LinkByName(NIC)
 	if err != nil {
 		panic(err)
@@ -58,8 +54,9 @@ func main() {
 		panic(err)
 	}
 
-	// Pre-generate a frame containing a DNS query.
+	defer xsk.Close()
 
+	// Pre-generate a frame
 	srcMAC, _ := hex.DecodeString(SrcMAC)
 	dstMAC, _ := hex.DecodeString(DstMAC)
 
@@ -84,106 +81,68 @@ func main() {
 		Seq:      1,
 	}
 
-	// udp.SetNetworkLayerForChecksum(ip)
+	// add payload
 	payload := make([]byte, PayloadSize)
 	for i := 0; i < len(payload); i++ {
 		payload[i] = byte(i)
 	}
 
-	// wm := icmp.Message{
-	// 	Type: ipv6.ICMPTypeEchoRequest, Code: 0,
-	// 	Body: &icmp.Echo{
-	// 		ID: os.Getpid() & 0xffff, Seq: 1,
-	// 		Data: []byte("HELLO-R-U-THERE"),
-	// 	},
-	// }
-	// icmp_bytes, err := wm.Marshal(nil)
-	// if err != nil {
-	// 	log.Fatal(err)
-	// }
-
+	// serialize
 	buf := gopacket.NewSerializeBuffer()
 	opts := gopacket.SerializeOptions{
 		FixLengths:       true,
 		ComputeChecksums: true,
 	}
 
-	fmt.Printf("sending icmp packets: %v (%v) to %v (%v)...\n", ip.SrcIP, eth.SrcMAC, ip.DstIP, eth.DstMAC)
-
 	err = gopacket.SerializeLayers(buf, opts, eth, ip, icmp, gopacket.Payload(payload))
 	if err != nil {
 		panic(err)
 	}
 	frameLen := len(buf.Bytes())
 
-	// buf.Bytes()[0x22] = 8
-	// buf.Bytes()[0x23] = 0
-
-	// Fill all the frames in UMEM with the pre-generated UDP packet.
-
+	// Fill all the frames in UMEM with the pre-generated packet.
 	descs := xsk.GetDescs(math.MaxInt32)
 	for i, _ := range descs {
 		frameLen = copy(xsk.GetFrame(descs[i]), buf.Bytes())
 	}
 
-	// Start sending the pre-generated frame as quickly as possible in an
-	// endless loop printing statistics of the number of sent frames and
-	// the number of sent bytes every second.
+	// go func() {
+	// 	var err error
+	// 	var prev xdp.Stats
+	// 	var cur xdp.Stats
+	// 	var numPkts uint64
+	// 	for i := uint64(0); ; i++ {
+	// 		time.Sleep(time.Duration(1) * time.Second)
+	// 		cur, err = xsk.Stats()
+	// 		if err != nil {
+	// 			panic(err)
+	// 		}
+	// 		numPkts = cur.Completed - prev.Completed
+	// 		fmt.Printf("%d packets/s (%d Mb/s)\n", numPkts, (numPkts*uint64(frameLen)*8)/(1000*1000))
+	// 		prev = cur
+	// 	}
+	// }()
 
 	fmt.Printf("sending icmp packets: %v (%v) to %v (%v)...\n", ip.SrcIP, eth.SrcMAC, ip.DstIP, eth.DstMAC)
 
-	go func() {
-		var err error
-		var prev xdp.Stats
-		var cur xdp.Stats
-		var numPkts uint64
-		for i := uint64(0); ; i++ {
-			time.Sleep(time.Duration(1) * time.Second)
-			cur, err = xsk.Stats()
+	// transmit
+	for i := 0; i < PingCount; i++ {
+
+		descs := xsk.GetDescs(xsk.NumFreeTxSlots())
+		if len(descs) > 0 {
+			fmt.Printf("Sending Ping Packet: %d\n", i)
+
+			for j, _ := range descs {
+				descs[j].Len = uint32(frameLen)
+			}
+
+			numPosted := xsk.Transmit(descs)
+			_, numCompleted, err := xsk.Poll(1)
 			if err != nil {
 				panic(err)
 			}
-			numPkts = cur.Completed - prev.Completed
-			fmt.Printf("%d packets/s (%d Mb/s)\n", numPkts, (numPkts*uint64(frameLen)*8)/(1000*1000))
-			prev = cur
+			fmt.Printf("Transmitted packets: %d posted, %d transmitted\n", numPosted, numCompleted)
 		}
-	}()
-
-	// var count = 0
-	for i := 0; i < PingCount; i++ {
-		fmt.Printf("Sending Ping Packet: %d\n", i)
-		descs := xsk.GetDescs(1)
-		for i, _ := range descs {
-			descs[i].Len = uint32(frameLen)
-		}
-		xsk.Transmit(descs)
-
-		_, _, err = xsk.Poll(-1)
-		if err != nil {
-			panic(err)
-		}
-
 		time.Sleep(time.Duration(150) * time.Millisecond)
 	}
 }
-
-// package main
-
-// import (
-// 	"fmt"
-// 	"log"
-// 	"net"
-// 	"syscall"
-
-// 	"golang.org/x/sys/unix"
-// )
-
-// func main() {
-// 	fd, err := syscall.Socket(unix.AF_XDP, syscall.SOCK_RAW, 0)
-// 	fmt.Println("Fd: ", fd)
-
-// 	err = syscall.Close(fd)
-// 	if err != nil {
-// 		panic(err)
-// 	}
-// }