diff --git a/.gitignore b/.gitignore
index 1262a976..6c69adbb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@
 /bash_completion
 /man_page
 /config_defaults
+/update_configuration
 
 # other created files
 /man_pages
@@ -24,3 +25,4 @@ _dist/
 config
 warewulf-*.tar.gz
 Defaults.mk
+
diff --git a/Makefile b/Makefile
index 8ba4ff4d..e0a6d4c3 100644
--- a/Makefile
+++ b/Makefile
@@ -225,11 +225,16 @@ man_pages: man_page
 	./man_page ./man_pages
 	cd man_pages; for i in wwctl*1; do echo "Compressing manpage: $$i"; gzip --force $$i; done
 
-config_defaults:
+config_defaults: vendor cmd/config_defaults/config_defaults.go
 	cd cmd/config_defaults && go build -ldflags="-X 'github.com/hpcng/warewulf/internal/pkg/warewulfconf.ConfigFile=./etc/warewulf.conf'\
 	 -X 'github.com/hpcng/warewulf/internal/pkg/node.ConfigFile=./etc/nodes.conf'"\
 	 -mod vendor -tags "$(WW_GO_BUILD_TAGS)" -o ../../config_defaults
 
+update_configuration: vendor cmd/update_configuration/update_configuration.go
+	cd cmd/update_configuration && go build -ldflags="-X 'github.com/hpcng/warewulf/internal/pkg/warewulfconf.ConfigFile=./etc/warewulf.conf'\
+	 -X 'github.com/hpcng/warewulf/internal/pkg/node.ConfigFile=./etc/nodes.conf'"\
+	 -mod vendor -tags "$(WW_GO_BUILD_TAGS)" -o ../../update_configuration
+
 warewulfconf: config_defaults
 	./config_defaults
 
@@ -255,6 +260,7 @@ clean:
 	rm -f Defaults.mk
 	rm -rf $(TOOLS_DIR)
 	rm -f config_defaults
+	rm -f update_configuration
 
 install: files install_wwclient
 
diff --git a/cmd/update_configuration/update_configuration.go b/cmd/update_configuration/update_configuration.go
new file mode 100644
index 00000000..f1532851
--- /dev/null
+++ b/cmd/update_configuration/update_configuration.go
@@ -0,0 +1,184 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"reflect"
+
+	"github.com/hpcng/warewulf/cmd/update_configuration/vers42"
+	"github.com/hpcng/warewulf/cmd/update_configuration/vers43"
+	"github.com/hpcng/warewulf/internal/pkg/buildconfig"
+	"github.com/hpcng/warewulf/internal/pkg/util"
+	"gopkg.in/yaml.v2"
+)
+
+var nowrite bool
+var quiet bool
+var confFile string
+
+const actvers int = 43
+
+type nodeVersionOnly struct {
+	WWInternal int `yaml:"WW_INTERNAL"`
+}
+
+func saveConf(conf interface{}) {
+	out, err := yaml.Marshal(conf)
+	if err != nil {
+		myprintf("Error in marshal of conf: %s\n", err)
+		os.Exit(1)
+	}
+	if nowrite {
+		fmt.Print(string(out))
+	} else {
+		err = util.CopyFile(confFile, confFile+".bak")
+		if err != nil {
+			myprintf("Could write file: %s\n", err)
+			os.Exit(1)
+		}
+		info, err := os.Stat(confFile)
+		if err != nil {
+			myprintf("Could not get file mode: %s\n", err)
+			os.Exit(1)
+		}
+		myprintf("writing configuration file %s as type %s\n", confFile, reflect.TypeOf(conf))
+		err = ioutil.WriteFile(confFile, out, info.Mode())
+		if err != nil {
+			myprintf("Could not write file: %s\n", err)
+			os.Exit(1)
+		}
+	}
+}
+
+func printB(x bool) string {
+	if x {
+		return "true"
+	}
+	return "false"
+}
+
+func update42to43(conf42 vers42.NodeConf) vers43.NodeConf {
+	ret := vers43.NodeConf{
+		Comment:       conf42.Comment,
+		ClusterName:   conf42.ClusterName,
+		ContainerName: conf42.ContainerName,
+		Init:          conf42.Init,
+		Root:          conf42.Root,
+		Discoverable:  printB(conf42.Discoverable),
+		Profiles:      conf42.Profiles,
+		Ipxe:          conf42.Ipxe}
+	if conf42.RuntimeOverlay != "" {
+		ret.RuntimeOverlay = []string{conf42.RuntimeOverlay}
+	}
+	if conf42.SystemOverlay != "" {
+		ret.SystemOverlay = []string{conf42.SystemOverlay}
+	}
+	if conf42.KernelArgs != "" || conf42.KernelVersion != "" {
+		ret.Kernel = new(vers43.KernelConf)
+		ret.Kernel.Override = conf42.KernelVersion
+		ret.Kernel.Args = conf42.KernelArgs
+
+	}
+	if conf42.IpmiUserName != "" || conf42.IpmiPassword != "" || conf42.IpmiIpaddr != "" ||
+		conf42.IpmiNetmask != "" || conf42.IpmiPort != "" || conf42.IpmiGateway != "" ||
+		conf42.IpmiInterface != "" {
+		ret.Ipmi = new(vers43.IpmiConf)
+		ret.Ipmi.UserName = conf42.IpmiUserName
+		ret.Ipmi.Password = conf42.IpmiPassword
+		ret.Ipmi.Ipaddr = conf42.IpmiIpaddr
+		ret.Ipmi.Netmask = conf42.IpmiNetmask
+		ret.Ipmi.Port = conf42.IpmiPort
+		ret.Ipmi.Gateway = conf42.IpmiGateway
+		ret.Ipmi.Interface = conf42.IpmiInterface
+	}
+	if len(conf42.Keys) != 0 {
+		ret.Keys = map[string]string{}
+		for k, v := range conf42.Keys {
+			ret.Keys[k] = v
+		}
+	}
+	ret.NetDevs = make(map[string]*vers43.NetDevs)
+	for devn, netdev := range conf42.NetDevs {
+		var device vers43.NetDevs = vers43.NetDevs{
+			Type:    netdev.Type,
+			Device:  devn,
+			Default: printB(netdev.Default),
+			Hwaddr:  netdev.Hwaddr,
+			Ipaddr:  netdev.Ipaddr,
+			IpCIDR:  netdev.IpCIDR,
+			Prefix:  netdev.Prefix,
+			Netmask: netdev.Netmask,
+			Gateway: netdev.Gateway}
+		ret.NetDevs[devn] = &device
+	}
+	return ret
+}
+
+func myprintf(format string, a ...interface{}) {
+	if !quiet {
+		fmt.Printf(format, a...)
+	}
+}
+
+func main() {
+	var endVers int
+	var startVers int
+	flag.StringVar(&confFile, "f", "", "Config file for update")
+	flag.IntVar(&endVers, "e", buildconfig.WWVer, "Final version of configuration file")
+	flag.IntVar(&startVers, "s", 0, "Start version  of configuration file, 0  is for autodetection")
+	flag.BoolVar(&nowrite, "n", false, "Do not write, just print new conf to terminal")
+	flag.BoolVar(&quiet, "q", false, "Do not print what the program is doing")
+	flag.Parse()
+	if confFile == "" {
+		myprintf("No config file given\n!")
+		os.Exit(1)
+	}
+	myprintf("Opening node configuration file: %s\n", confFile)
+	data, err := ioutil.ReadFile(confFile)
+	if err != nil {
+		myprintf("Could open file %v\n", err)
+		os.Exit(1)
+	}
+	var getConf nodeVersionOnly
+	myprintf("Unmarshaling the node configuration\n")
+	err = yaml.Unmarshal(data, &getConf)
+	if err != nil {
+		myprintf("Could not unmarshall: %v\n", err)
+	}
+	myprintf("Got version %v in %s\n", getConf.WWInternal, confFile)
+	if getConf.WWInternal == actvers {
+		myprintf("On actual version, bailing out\n")
+		os.Exit(0)
+	}
+	if startVers == 0 && getConf.WWInternal == 0 {
+		startVers = 42
+	}
+	var conf42 vers42.NodeYaml
+	conf42.NodeProfiles = make(map[string]*vers42.NodeConf)
+	conf42.Nodes = make(map[string]*vers42.NodeConf)
+
+	var conf43 vers43.NodeYaml
+	conf43.NodeProfiles = make(map[string]*vers43.NodeConf)
+	conf43.Nodes = make(map[string]*vers43.NodeConf)
+	conf43.WWInternal = 43
+
+	if startVers == 42 {
+		myprintf("Unmarshaling the node configuration vers 42\n")
+		err = yaml.Unmarshal(data, &conf42)
+		if err != nil {
+			myprintf("Could not unmarshall version 42: %v\n", err)
+		}
+		for pname, profile := range conf42.NodeProfiles {
+			p43 := update42to43(*profile)
+			conf43.NodeProfiles[pname] = &p43
+		}
+		for nname, node := range conf42.Nodes {
+			n43 := update42to43(*node)
+			conf43.Nodes[nname] = &n43
+		}
+		saveConf(conf43)
+
+	}
+}
diff --git a/cmd/update_configuration/vers42/datastructure.go b/cmd/update_configuration/vers42/datastructure.go
new file mode 100644
index 00000000..787cc5ce
--- /dev/null
+++ b/cmd/update_configuration/vers42/datastructure.go
@@ -0,0 +1,46 @@
+package vers42
+
+/******
+ * YAML data representations
+ ******/
+
+//type nodeYaml struct {
+type NodeYaml struct { // <-Needs to be exported
+	NodeProfiles map[string]*NodeConf
+	Nodes        map[string]*NodeConf
+}
+
+type NodeConf struct {
+	Comment        string              `yaml:"comment,omitempty"`
+	ClusterName    string              `yaml:"cluster name,omitempty"`
+	ContainerName  string              `yaml:"container name,omitempty"`
+	Ipxe           string              `yaml:"ipxe template,omitempty"`
+	KernelVersion  string              `yaml:"kernel version,omitempty"`
+	KernelArgs     string              `yaml:"kernel args,omitempty"`
+	IpmiUserName   string              `yaml:"ipmi username,omitempty"`
+	IpmiPassword   string              `yaml:"ipmi password,omitempty"`
+	IpmiIpaddr     string              `yaml:"ipmi ipaddr,omitempty"`
+	IpmiNetmask    string              `yaml:"ipmi netmask,omitempty"`
+	IpmiPort       string              `yaml:"ipmi port,omitempty"`
+	IpmiGateway    string              `yaml:"ipmi gateway,omitempty"`
+	IpmiInterface  string              `yaml:"ipmi interface,omitempty"`
+	RuntimeOverlay string              `yaml:"runtime overlay,omitempty"`
+	SystemOverlay  string              `yaml:"system overlay,omitempty"`
+	Init           string              `yaml:"init,omitempty"`
+	Root           string              `yaml:"root,omitempty"`
+	Discoverable   bool                `yaml:"discoverable,omitempty"`
+	Profiles       []string            `yaml:"profiles,omitempty"`
+	NetDevs        map[string]*NetDevs `yaml:"network devices,omitempty"`
+	Keys           map[string]string   `yaml:"keys,omitempty"`
+}
+
+type NetDevs struct {
+	Type    string `yaml:"type,omitempty"`
+	Default bool   `yaml:"default"`
+	Hwaddr  string
+	Ipaddr  string
+	IpCIDR  string
+	Prefix  string
+	Netmask string
+	Gateway string `yaml:"gateway,omitempty"`
+}
diff --git a/cmd/update_configuration/vers42/nodes.conf b/cmd/update_configuration/vers42/nodes.conf
new file mode 100644
index 00000000..792e48a2
--- /dev/null
+++ b/cmd/update_configuration/vers42/nodes.conf
@@ -0,0 +1,22 @@
+nodeprofiles:
+  default:
+    comment: This profile is automatically included for each node
+    runtime overlay: "generic"
+    discoverable: false
+  leap:
+    comment: openSUSE leap
+    kernel version: "5.14.21"
+    ipmi netmask: "255.255.255.0"
+    keys:
+      foo: baar
+    network devices:
+      lan1:
+        gateway: 1.1.1.1
+nodes:
+  node01:
+    system overlay: "nodeoverlay"
+    discoverable: true
+    network devices:
+      eth0:
+        ipaddr: 1.2.3.4
+        default: true
diff --git a/cmd/update_configuration/vers42/nodes.conf.bak b/cmd/update_configuration/vers42/nodes.conf.bak
new file mode 100644
index 00000000..792e48a2
--- /dev/null
+++ b/cmd/update_configuration/vers42/nodes.conf.bak
@@ -0,0 +1,22 @@
+nodeprofiles:
+  default:
+    comment: This profile is automatically included for each node
+    runtime overlay: "generic"
+    discoverable: false
+  leap:
+    comment: openSUSE leap
+    kernel version: "5.14.21"
+    ipmi netmask: "255.255.255.0"
+    keys:
+      foo: baar
+    network devices:
+      lan1:
+        gateway: 1.1.1.1
+nodes:
+  node01:
+    system overlay: "nodeoverlay"
+    discoverable: true
+    network devices:
+      eth0:
+        ipaddr: 1.2.3.4
+        default: true
diff --git a/cmd/update_configuration/vers43/datastructure.go b/cmd/update_configuration/vers43/datastructure.go
new file mode 100644
index 00000000..eda98449
--- /dev/null
+++ b/cmd/update_configuration/vers43/datastructure.go
@@ -0,0 +1,65 @@
+package vers43
+
+/******
+ * YAML data representations
+ ******/
+
+//type nodeYaml struct {
+type NodeYaml struct { // <- needs to be exported
+	WWInternal   int `yaml:"WW_INTERNAL"`
+	NodeProfiles map[string]*NodeConf
+	Nodes        map[string]*NodeConf
+}
+
+/*
+NodeConf is the datastructure which is stored on disk.
+*/
+type NodeConf struct {
+	Comment        string              `yaml:"comment,omitempty"`
+	ClusterName    string              `yaml:"cluster name,omitempty"`
+	ContainerName  string              `yaml:"container name,omitempty"`
+	Ipxe           string              `yaml:"ipxe template,omitempty"`
+	RuntimeOverlay []string            `yaml:"runtime overlay,omitempty"`
+	SystemOverlay  []string            `yaml:"system overlay,omitempty"`
+	Kernel         *KernelConf         `yaml:"kernel,omitempty"`
+	Ipmi           *IpmiConf           `yaml:"ipmi,omitempty"`
+	Init           string              `yaml:"init,omitempty"`
+	Root           string              `yaml:"root,omitempty"`
+	AssetKey       string              `yaml:"asset key,omitempty"`
+	Discoverable   string              `yaml:"discoverable,omitempty"`
+	Profiles       []string            `yaml:"profiles,omitempty"`
+	NetDevs        map[string]*NetDevs `yaml:"network devices,omitempty"`
+	Tags           map[string]string   `yaml:"tags,omitempty"`
+	Keys           map[string]string   `yaml:"keys,omitempty"` // Reverse compatibility
+}
+
+type IpmiConf struct {
+	UserName  string `yaml:"username,omitempty"`
+	Password  string `yaml:"password,omitempty"`
+	Ipaddr    string `yaml:"ipaddr,omitempty"`
+	Netmask   string `yaml:"netmask,omitempty"`
+	Port      string `yaml:"port,omitempty"`
+	Gateway   string `yaml:"gateway,omitempty"`
+	Interface string `yaml:"interface,omitempty"`
+	Write     bool   `yaml:"write,omitempty"`
+}
+type KernelConf struct {
+	Version  string `yaml:"version,omitempty"`
+	Override string `yaml:"override,omitempty"`
+	Args     string `yaml:"args,omitempty"`
+}
+
+type NetDevs struct {
+	Type    string            `yaml:"type,omitempty"`
+	OnBoot  string            `yaml:"onboot,omitempty"`
+	Device  string            `yaml:"device,omitempty"`
+	Hwaddr  string            `yaml:"hwaddr,omitempty"`
+	Ipaddr  string            `yaml:"ipaddr,omitempty"`
+	IpCIDR  string            `yaml:"ipcidr,omitempty"`
+	Ipaddr6 string            `yaml:"ip6addr,omitempty"`
+	Prefix  string            `yaml:"prefix,omitempty"`
+	Netmask string            `yaml:"netmask,omitempty"`
+	Gateway string            `yaml:"gateway,omitempty"`
+	Default string            `yaml:"default,omitempty"`
+	Tags    map[string]string `yaml:"tags,omitempty"`
+}
diff --git a/cmd/update_configuration/vers43/nodes.conf b/cmd/update_configuration/vers43/nodes.conf
new file mode 100644
index 00000000..acbf5b96
--- /dev/null
+++ b/cmd/update_configuration/vers43/nodes.conf
@@ -0,0 +1,32 @@
+WW_INTERNAL: 43
+nodeprofiles:
+  default:
+    comment: This profile is automatically included for each node
+    runtime overlay:
+    - generic
+    discoverable: "false"
+  leap:
+    comment: openSUSE leap
+    kernel:
+      override: 5.14.21
+    ipmi:
+      netmask: 255.255.255.0
+    discoverable: "false"
+    network devices:
+      lan1:
+        device: lan1
+        gateway: 1.1.1.1
+        default: "false"
+    keys:
+      foo: baar
+nodes:
+  node01:
+    system overlay:
+    - nodeoverlay
+    discoverable: "true"
+    network devices:
+      eth0:
+        device: eth0
+        ipaddr: 1.2.3.4
+        default: "true"
+