diff --git a/conf/agent/config.exemple.yml b/conf/agent/config.exemple.yml
index 5bd1dfd..bc1d437 100644
--- a/conf/agent/config.exemple.yml
+++ b/conf/agent/config.exemple.yml
@@ -1,7 +1,9 @@
 database:
   path: "/var/lib/two/data/"
 
+default_interface: br-000000
+
 interfaces:
   vms: br-000000
   internet: br-000000
-  admin: br-000000
\ No newline at end of file
+  admin: br-000000
diff --git a/internal/config/agent/struct.go b/internal/config/agent/struct.go
index 21dde0d..1c9fc9f 100644
--- a/internal/config/agent/struct.go
+++ b/internal/config/agent/struct.go
@@ -20,7 +20,8 @@ type Config struct {
 		Count      int `mapstructure:"count"`
 		BufferSize int `mapstructure:"buffer_size"`
 	} `mapstructure:"worker"`
-	Interfaces map[string]string `mapstructure:"interfaces"`
+	DefaultInterface string            `mapstructure:"default_interface"`
+	Interfaces       map[string]string `mapstructure:"interfaces"`
 }
 
 func LoadConfig(path string) (*Config, error) {
@@ -35,6 +36,7 @@ func LoadConfig(path string) (*Config, error) {
 	v.SetDefault("prometheus.port", 9090)
 	v.SetDefault("worker.count", 4)
 	v.SetDefault("worker.buffer_size", 100)
+	v.SetDefault("default_interface", "br-000000")
 
 	v.ReadInConfig()
 
diff --git a/internal/dispatcher/subnet_commands.go b/internal/dispatcher/subnet_commands.go
index c2a0cff..0d471c3 100644
--- a/internal/dispatcher/subnet_commands.go
+++ b/internal/dispatcher/subnet_commands.go
@@ -23,7 +23,7 @@ type CreateSubnetCommand struct {
 func (c CreateSubnetCommand) Execute(db *badger.DB, cfg *configuration.Config) error {
 	localIface, ok := cfg.Interfaces[c.IfaceType]
 	if !ok {
-		return fmt.Errorf("unknown iface_type %q: not found in config", c.IfaceType)
+		localIface = cfg.DefaultInterface
 	}
 	kv.AddInDB(db, "subnet/"+c.Name+"/state", "creating")
 	kv.AddInDB(db, "subnet/"+c.Name+"/vpc", c.VPC)