diff --git a/cmd/start.go b/cmd/start.go
index 593e311..964c2d3 100644
--- a/cmd/start.go
+++ b/cmd/start.go
@@ -256,10 +256,10 @@ func prepareJailedZfsDatasets(jail *Jail) error {
 func StartJail(args []string) {
 	// jail we have to start
 	var cj *Jail
-
+	
 	for _, j := range args {
 		fmt.Printf("> Starting jail %s\n", j)
-
+		
 		for i, rj := range gJails {
 			if rj.Name == j {
 				// Get jail reference, not a copy of it; So we can modify attributes
@@ -271,12 +271,49 @@ func StartJail(args []string) {
 			fmt.Printf("Jail not found: %s\n", j)
 			continue
 		}
-
+		
 		if cj.Running == true {
 			fmt.Printf("Jail %s is already running!\n", cj.Name)
 			continue
 		}
-
+		
+		if len(cj.hostid) > 0 && cj.Hostid_strict_check == true {
+			hostid, err := ioutil.ReadFile("/etc/hostid")
+			if err != nil {
+				return err
+			}
+			hostid = []byte(strings.Replace(string(hostid), "\n", "", -1))
+			if strings.EqualFold(hostid, cj.hostid) == false {
+				fmt.Printf("hostid is not matching and hostid_strict_check is on. Not starting jail.\n")
+				return
+			}
+		}
+		
+		var props_missing []string
+		// DHCP can also be set with "DHCP" value in ip4_addr
+		if cj.Dhcp == true || strings.EqualFold(cj.Ip4_addr, "DHCP") == true {
+			if cj.Bpf == 0 {
+				props_missing = append(props_missing, fmt.Sprintf("%s: dhcp requires bpf", cj.Name))
+			}
+			if cj.Vnet == 0 {
+				props_missing = append(props_missing, fmt.Sprintf("%s: dhcp requires vnet", cj.Name))
+			}
+		}
+		// TODO : Check that this nat_forwards exemple is OK : 
+		// tcp(80:8080),tcp(3300-3310:33060-33070)
+		// If OK, it should map jail port 80 to 8080 on the host
+		//   and range 3300-3310 on jail to 33060-33070 on the host
+		if cj.Nat > 0 && strings.EqualFold(cj.Nat_forwards, "none") == false {
+			// If NAT && port forwarding is enabled, check that port does not conflict 
+			//   with another running jail
+			for _, j := range gJails {
+				if j.Running == false {
+					continue
+				}
+				// TODO : check!
+			}
+		}
+		
 		fmt.Printf("  > Mount special filesystems:\n")
 		err := mountAllJailFsFromHost(cj)
 		if err != nil {
@@ -284,7 +321,7 @@ func StartJail(args []string) {
 		} else {
 			fmt.Printf("  > Mount special filesystems: OK\n")
 		}
-
+		
 		if cj.Config.Jail_zfs > 0 {
 			fmt.Printf("  > Prepare ZFS Datasets:\n")
 			err := prepareJailedZfsDatasets(cj)
@@ -294,8 +331,8 @@ func StartJail(args []string) {
 				fmt.Printf("  > Prepare ZFS Datasets: OK\n")
 			}
 		}
-
-
+		
+		
 /*
 		out, err := executeCommand(fmt.Sprintf("rctl jail:%s", cj.InternalName))
 		if err == nil && len(out) > 0 {