diff --git a/discovery/Host.go b/discovery/Host.go
index f56ae0e..7061225 100644
--- a/discovery/Host.go
+++ b/discovery/Host.go
@@ -7,11 +7,14 @@ import (
 
 const (
 	DefaultOsType     = "UNKNOWN"
-	DefaultHostType   = "HOST"
 	DefaultHostVendor = "UNKNOWN"
 	DefaultHostModel  = "UNKNOWN"
 )
 
+var (
+	DefaultHostType = meta.MetaHostTypeEnumHost.String()
+)
+
 type Host struct {
 	MetaIPType *meta.MetaIPType `json:"metaIPType,omitempty"`
 	Name       string           `json:"name,omitempty"`
diff --git a/discovery/Service.go b/discovery/Service.go
index 205b694..a92d0d9 100644
--- a/discovery/Service.go
+++ b/discovery/Service.go
@@ -6,11 +6,14 @@ import (
 )
 
 const (
-	DefaultServiceType    = "ETC"
 	DefaultServiceVendor  = "UNKNOWN"
 	DefaultServiceVersion = "UNKNOWN"
 )
 
+var (
+	DefaultServiceType = meta.MetaServiceTypeEnumUNKNOWN.String()
+)
+
 type Service struct {
 	MetaCryptoType *meta.MetaCryptoType `json:"metaCryptoType,omitempty"`
 	Key            string               `json:"key,omitempty"`
diff --git a/meta/MetaHostType.go b/meta/MetaHostType.go
new file mode 100644
index 0000000..0db46e6
--- /dev/null
+++ b/meta/MetaHostType.go
@@ -0,0 +1,53 @@
+package meta
+
+import (
+	"encoding/json"
+
+	"git.loafle.net/overflow/model/util"
+)
+
+type MetaHostType struct {
+	ID         json.Number     `json:"id,Number,omitempty"`
+	Name       string          `json:"name,omitempty"`
+	Key        string          `json:"key,omitempty"`
+	CreateDate *util.Timestamp `json:"createDate,omitempty"`
+}
+
+type MetaHostTypeEnum int
+
+const (
+	MetaHostTypeEnumHost MetaHostTypeEnum = iota + 1
+	MetaHostTypeEnumNAS
+	MetaHostTypeEnumPrinter
+	MetaHostTypeEnumRouter
+)
+
+var (
+	metaHostTypeEnumID = map[MetaHostTypeEnum]string{
+		MetaHostTypeEnumHost:    "HOST",
+		MetaHostTypeEnumNAS:     "NAS",
+		MetaHostTypeEnumPrinter: "PRINTER",
+		MetaHostTypeEnumRouter:  "ROUTER",
+	}
+
+	metaHostTypeEnumKey = map[string]MetaHostTypeEnum{
+		"HOST":    MetaHostTypeEnumHost,
+		"NAS":     MetaHostTypeEnumNAS,
+		"PRINTER": MetaHostTypeEnumPrinter,
+		"ROUTER":  MetaHostTypeEnumRouter,
+	}
+)
+
+func (e MetaHostTypeEnum) String() string {
+	return metaHostTypeEnumID[e]
+}
+
+func ToMetaHostTypeEnum(v *MetaHostType) MetaHostTypeEnum {
+	return metaHostTypeEnumKey[v.Key]
+}
+
+func ToMetaHostType(v MetaHostTypeEnum) *MetaHostType {
+	return &MetaHostType{
+		Key: metaHostTypeEnumID[v],
+	}
+}
diff --git a/meta/MetaServiceType.go b/meta/MetaServiceType.go
new file mode 100644
index 0000000..1d0e859
--- /dev/null
+++ b/meta/MetaServiceType.go
@@ -0,0 +1,65 @@
+package meta
+
+import (
+	"encoding/json"
+
+	"git.loafle.net/overflow/model/util"
+)
+
+type MetaServiceType struct {
+	ID         json.Number     `json:"id,Number,omitempty"`
+	Name       string          `json:"name,omitempty"`
+	Key        string          `json:"key,omitempty"`
+	CreateDate *util.Timestamp `json:"createDate,omitempty"`
+}
+
+type MetaServiceTypeEnum int
+
+const (
+	MetaServiceTypeEnumUNKNOWN MetaServiceTypeEnum = iota + 1
+	MetaServiceTypeEnumNetwork
+	MetaServiceTypeEnumDatabase
+	MetaServiceTypeEnumNoSQL
+	MetaServiceTypeEnumMail
+	MetaServiceTypeEnumSearch
+	MetaServiceTypeEnumWeb
+	MetaServiceTypeEnumWAS
+)
+
+var (
+	metaServiceTypeEnumID = map[MetaServiceTypeEnum]string{
+		MetaServiceTypeEnumUNKNOWN:  "UNKNOWN",
+		MetaServiceTypeEnumNetwork:  "NETWORK",
+		MetaServiceTypeEnumDatabase: "DATABASE",
+		MetaServiceTypeEnumNoSQL:    "NOSQL",
+		MetaServiceTypeEnumMail:     "MAIL",
+		MetaServiceTypeEnumSearch:   "SEARCH",
+		MetaServiceTypeEnumWeb:      "WEB",
+		MetaServiceTypeEnumWAS:      "WAS",
+	}
+
+	metaServiceTypeEnumKey = map[string]MetaServiceTypeEnum{
+		"UNKNOWN":  MetaServiceTypeEnumUNKNOWN,
+		"NETWORK":  MetaServiceTypeEnumNetwork,
+		"DATABASE": MetaServiceTypeEnumDatabase,
+		"NOSQL":    MetaServiceTypeEnumNoSQL,
+		"MAIL":     MetaServiceTypeEnumMail,
+		"SEARCH":   MetaServiceTypeEnumSearch,
+		"WEB":      MetaServiceTypeEnumWeb,
+		"WAS":      MetaServiceTypeEnumWAS,
+	}
+)
+
+func (e MetaServiceTypeEnum) String() string {
+	return metaServiceTypeEnumID[e]
+}
+
+func ToMetaServiceTypeEnum(v *MetaServiceType) MetaServiceTypeEnum {
+	return metaServiceTypeEnumKey[v.Key]
+}
+
+func ToMetaServiceType(v MetaServiceTypeEnum) *MetaServiceType {
+	return &MetaServiceType{
+		Key: metaServiceTypeEnumID[v],
+	}
+}