diff --git a/cmd/devp2p/discv4cmd.go b/cmd/devp2p/discv4cmd.go
index 0117c7eb82..00a1abb2ba 100644
--- a/cmd/devp2p/discv4cmd.go
+++ b/cmd/devp2p/discv4cmd.go
@@ -98,7 +98,7 @@ var (
 var (
 	bootnodesFlag = &cli.StringFlag{
 		Name:  "bootnodes",
-		Usage: "Comma separated nodes used for bootstrapping",
+		Usage: "Comma separated nodes used for bootstrapping(default is mainnet bootnodes)",
 	}
 	nodekeyFlag = &cli.StringFlag{
 		Name:  "nodekey",
@@ -143,7 +143,7 @@ var discoveryNodeFlags = []cli.Flag{
 
 func discv4Ping(ctx *cli.Context) error {
 	n := getNodeArg(ctx)
-	disc := startV4(ctx)
+	disc, _ := startV4(ctx)
 	defer disc.Close()
 
 	start := time.Now()
@@ -156,7 +156,7 @@ func discv4Ping(ctx *cli.Context) error {
 
 func discv4RequestRecord(ctx *cli.Context) error {
 	n := getNodeArg(ctx)
-	disc := startV4(ctx)
+	disc, _ := startV4(ctx)
 	defer disc.Close()
 
 	respN, err := disc.RequestENR(n)
@@ -169,7 +169,7 @@ func discv4RequestRecord(ctx *cli.Context) error {
 
 func discv4Resolve(ctx *cli.Context) error {
 	n := getNodeArg(ctx)
-	disc := startV4(ctx)
+	disc, _ := startV4(ctx)
 	defer disc.Close()
 
 	fmt.Println(disc.Resolve(n).String())
@@ -197,8 +197,12 @@ func discv4ResolveJSON(ctx *cli.Context) error {
 	}
 
 	// Run the crawler.
-	disc := startV4(ctx)
+	disc, config := startV4(ctx)
 	defer disc.Close()
+
+	if len(inputSet) == 0 {
+		inputSet.add(config.Bootnodes...)
+	}
 	c := newCrawler(inputSet, disc, enode.IterNodes(nodeargs))
 	c.revalidateInterval = 0
 	output := c.run(0, 1)
@@ -211,13 +215,17 @@ func discv4Crawl(ctx *cli.Context) error {
 		return errors.New("need nodes file as argument")
 	}
 	nodesFile := ctx.Args().First()
-	var inputSet nodeSet
+	inputSet := make(nodeSet)
 	if common.FileExist(nodesFile) {
 		inputSet = loadNodesJSON(nodesFile)
 	}
 
-	disc := startV4(ctx)
+	disc, config := startV4(ctx)
 	defer disc.Close()
+
+	if len(inputSet) == 0 {
+		inputSet.add(config.Bootnodes...)
+	}
 	c := newCrawler(inputSet, disc, disc.RandomNodes())
 	c.revalidateInterval = 10 * time.Minute
 	output := c.run(ctx.Duration(crawlTimeoutFlag.Name), ctx.Int(crawlParallelismFlag.Name))
@@ -238,14 +246,14 @@ func discv4Test(ctx *cli.Context) error {
 }
 
 // startV4 starts an ephemeral discovery V4 node.
-func startV4(ctx *cli.Context) *discover.UDPv4 {
+func startV4(ctx *cli.Context) (*discover.UDPv4, discover.Config) {
 	ln, config := makeDiscoveryConfig(ctx)
 	socket := listen(ctx, ln)
 	disc, err := discover.ListenV4(socket, ln, config)
 	if err != nil {
 		exit(err)
 	}
-	return disc
+	return disc, config
 }
 
 func makeDiscoveryConfig(ctx *cli.Context) (*enode.LocalNode, discover.Config) {