diff --git a/cmd/tomo/main.go b/cmd/tomo/main.go
index 3afa5d36bd..de76c9c72f 100644
--- a/cmd/tomo/main.go
+++ b/cmd/tomo/main.go
@@ -356,8 +356,8 @@ func startNode(ctx *cli.Context, stack *node.Node, cfg tomoConfig) {
 					}
 				case <-core.M1Ch:
 					err := ethereum.BlockChain().UpdateM1()
-					if(err !=nil){
-						log.Error("Error when update M1",err)
+					if err != nil {
+						log.Error("Error when update M1", err)
 					}
 				}
 			}
diff --git a/core/blockchain.go b/core/blockchain.go
index 1c8884d6af..7ea36b2be1 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -698,7 +698,7 @@ func (bc *BlockChain) procFutureBlocks() {
 type WriteStatus byte
 
 const (
-	NonStatTy   WriteStatus = iota
+	NonStatTy WriteStatus = iota
 	CanonStatTy
 	SideStatTy
 )
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index 4180ae2eaa..183c36e716 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -1350,7 +1350,7 @@ func (d *Downloader) processFullSyncContent() error {
 					// prepare set of masternodes for the next epoch
 					if (inserts[len(inserts)-1].Header.Number.Uint64() % epoch) == (epoch - gap) {
 						err := d.blockchain.UpdateM1()
-						if (err != nil) {
+						if err != nil {
 							log.Error("Error when update M1", err)
 						}
 					}
diff --git a/p2p/discover/udp.go b/p2p/discover/udp.go
index c8491963f7..335108f233 100644
--- a/p2p/discover/udp.go
+++ b/p2p/discover/udp.go
@@ -59,7 +59,7 @@ const (
 
 // RPC packet types
 const (
-	pingPacket        = iota + 1 // zero is 'reserved'
+	pingPacket = iota + 1 // zero is 'reserved'
 	pongPacket
 	findnodePacket
 	neighborsPacket
diff --git a/p2p/discover/udp_test.go b/p2p/discover/udp_test.go
index ee4474d323..ef7142cb3f 100644
--- a/p2p/discover/udp_test.go
+++ b/p2p/discover/udp_test.go
@@ -391,7 +391,7 @@ var testPackets = []struct {
 	wantPacket interface{}
 }{
 	{
-		input: "71dbda3a79554728d4f94411e42ee1f8b0d561c10e1e5f5893367948c6a7d70bb87b235fa28a77070271b6c164a2dce8c7e13a5739b53b5e96f2e5acb0e458a02902f5965d55ecbeb2ebb6cabb8b2b232896a36b737666c55265ad0a68412f250001ea04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a355",
+		input: "95a4d7d1909e6a58f115e9a451d47a8f016776a8874140366e702e33e85c7b4cd58a82ebece6acd0973342b66b9e716fece46b5c67a3560fc8624063dd15a310469de42ca599474b9d8cb6eb8dc41b0d5236539ea7ae10ef3c630cd94faefd800005ea04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a355",
 		wantPacket: &ping{
 			Version:    4,
 			From:       rpcEndpoint{net.ParseIP("127.0.0.1").To4(), 3322, 5544},
@@ -401,7 +401,7 @@ var testPackets = []struct {
 		},
 	},
 	{
-		input: "e9614ccfd9fc3e74360018522d30e1419a143407ffcce748de3e22116b7e8dc92ff74788c0b6663aaa3d67d641936511c8f8d6ad8698b820a7cf9e1be7155e9a241f556658c55428ec0563514365799a4be2be5a685a80971ddcfa80cb422cdd0101ec04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a3550102",
+		input: "57b1c182cc24e21e9297baa70d57a67ade498439123c968ffc048541addf9d463d1d25d10cf473a7f90a3efd6a070818097ebeaef58cd53843cb3af28acaee354272cfe7801b7fa7dbd8aa13309b6059fce877ad376c8dad7524dc34de626bd80105ec04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a3550102",
 		wantPacket: &ping{
 			Version:    4,
 			From:       rpcEndpoint{net.ParseIP("127.0.0.1").To4(), 3322, 5544},
@@ -411,7 +411,7 @@ var testPackets = []struct {
 		},
 	},
 	{
-		input: "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",
+		input: "e3e987421accd2c75967d4a7229c436c18760def054738d8d9669697ee4726cdc9949c51df3e90d795d33d3f57d508c4687913338f6eb9caa89873aaae9dd49a5473ade5ea452c4df9d1f842eadf03439dbc373c0de8b20b412b6760d7b479140105f83e82022bd79020010db83c4d001500000000abcdef12820cfa8215a8d79020010db885a308d313198a2e037073488208ae82823a8443b9a355c50102030405",
 		wantPacket: &ping{
 			Version:    555,
 			From:       rpcEndpoint{net.ParseIP("2001:db8:3c4d:15::abcd:ef12"), 3322, 5544},
@@ -475,7 +475,6 @@ var testPackets = []struct {
 func TestForwardCompatibility(t *testing.T) {
 	testkey, _ := crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 	wantNodeID := PubkeyID(&testkey.PublicKey)
-
 	for _, test := range testPackets {
 		input, err := hex.DecodeString(test.input)
 		if err != nil {