diff --git a/cli/man/ngcli.1 b/cli/man/ngcli.1
index 66101c2..71c02a6 100644
--- a/cli/man/ngcli.1
+++ b/cli/man/ngcli.1
@@ -1,4 +1,4 @@
-.TH NGCLI "1" "October 2013" "NgAdmin 0.1" "User Commands"
+.TH NGCLI "1" "September 2014" "NgAdmin 0.1" "User Commands"
 .SH NAME
 ngcli \- command line interface tool for GS10[58]E administration
 .
@@ -154,6 +154,18 @@ switches. This command delogs from the current switch, whether the login
 attempt is successful or not.
 .
 .TP
+\fBloop disable
+Disable loop detection.
+.
+.TP
+\fBloop enable
+Enable loop detection.
+.
+.TP
+\fBloop show
+Show loop detection configuration.
+.
+.TP
 \fBmirror disable
 Disable port mirroring.
 .
diff --git a/cli/src/Makefile.am b/cli/src/Makefile.am
index c756408..b23cedd 100644
--- a/cli/src/Makefile.am
+++ b/cli/src/Makefile.am
@@ -3,9 +3,10 @@ bin_PROGRAMS = ngcli
 noinst_HEADERS = commands.h common.h
 
 ngcli_SOURCES = admin.c com_bitrate.c com_cabletest.c com_defaults.c com_firmware.c \
-		com_help.c com_igmp.c com_list.c com_login.c commands.c com_mirror.c \
-		common.c com_name.c com_netconf.c com_password.c com_ports.c com_qos.c \
-		com_quit.c com_restart.c com_scan.c com_stormfilter.c com_tree.c com_vlan.c
+		com_help.c com_igmp.c com_list.c com_login.c com_loop.c commands.c \
+		com_mirror.c common.c com_name.c com_netconf.c com_password.c \
+		com_ports.c com_qos.c com_quit.c com_restart.c com_scan.c \
+		com_stormfilter.c com_tree.c com_vlan.c
 ngcli_CPPFLAGS = -I$(top_srcdir)/raw/include/ -I$(top_srcdir)/lib/include/
 ngcli_LDADD = $(top_builddir)/raw/src/librawnsdp.la $(top_builddir)/lib/src/libngadmin.la $(READLINE_LIBS)
 
diff --git a/cli/src/com_loop.c b/cli/src/com_loop.c
new file mode 100644
index 0000000..45c4acd
--- /dev/null
+++ b/cli/src/com_loop.c
@@ -0,0 +1,69 @@
+
+#include "commands.h"
+
+
+int do_loop_enable (int argc, const char **argv UNUSED, struct ngadmin *nga)
+{
+	int i;
+	
+	
+	if (argc > 0) {
+		printf("this command takes no argument\n");
+		return 1;
+	}
+	
+	i = ngadmin_setLoopDetectionState(nga, 1);
+	printErrCode(i);
+	
+	
+	return 0;
+}
+
+
+int do_loop_disable (int argc, const char **argv UNUSED, struct ngadmin *nga)
+{
+	int i;
+	
+	
+	if (argc > 0) {
+		printf("this command takes no argument\n");
+		return 1;
+	}
+	
+	i = ngadmin_setLoopDetectionState(nga, 0);
+	printErrCode(i);
+	
+	
+	return 0;
+}
+
+
+int do_loop_show (int argc, const char **argv UNUSED, struct ngadmin *nga)
+{
+	int i, s;
+	const struct swi_attr *sa;
+	
+	
+	if (argc > 0) {
+		printf("this command takes no argument\n");
+		return 1;
+	}
+	
+	sa = ngadmin_getCurrentSwitch(nga);
+	if (sa == NULL) {
+		printf("must be logged\n");
+		return 1;
+	}
+	
+	i = ngadmin_getLoopDetectionState(nga, &s);
+	if (i != ERR_OK) {
+		printErrCode(i);
+		return 1;
+	}
+	
+	printf("loop detection is %s\n", s ? "enabled" : "disabled");
+	
+	return 0;
+}
+
+
diff --git a/cli/src/commands.c b/cli/src/commands.c
index 7662c72..df4c93d 100644
--- a/cli/src/commands.c
+++ b/cli/src/commands.c
@@ -37,6 +37,12 @@ int do_list (int argc, const char **argv, struct ngadmin *nga);
 int do_login (int argc, const char **argv, struct ngadmin *nga);
 
 
+/* loop */
+int do_loop_enable (int argc, const char **argv, struct ngadmin *nga);
+int do_loop_disable (int argc, const char **argv, struct ngadmin *nga);
+int do_loop_show (int argc, const char **argv, struct ngadmin *nga);
+
+
 /* mirror */
 int do_mirror_disable (int argc, const char **argv, struct ngadmin *nga);
 int do_mirror_set (int argc, const char **argv, struct ngadmin *nga);
@@ -133,6 +139,12 @@ COM_ROOT_START(commands)
 	
 	COM_TERM(login, do_login)
 	
+	COM_START(loop)
+		COM_TERM(disable, do_loop_disable)
+		COM_TERM(enable, do_loop_enable)
+		COM_TERM(show, do_loop_show)
+	COM_END
+	
 	COM_START(mirror)
 		COM_TERM(disable, do_mirror_disable)
 		COM_TERM(set, do_mirror_set)
diff --git a/lib/include/ngadmin.h b/lib/include/ngadmin.h
index 50fffa9..a7e17de 100644
--- a/lib/include/ngadmin.h
+++ b/lib/include/ngadmin.h
@@ -807,6 +807,28 @@ int ngadmin_getAllPVID (struct ngadmin *nga, unsigned short *ports);
 int ngadmin_setPVID (struct ngadmin *nga, unsigned char port, unsigned short vlan);
 
 
+/**
+ * Get the loop detection state. 
+ * Retrieves the loop detection state. 
+ * @note You must be logged on a switch. 
+ * @param nga A pointer to the ngadmin structure. 
+ * @param s A pointer to an integer which will receive 0 or 1. 
+ * @return ERR_OK when everything is well or an error code otherwise. 
+ **/
+int ngadmin_getLoopDetectionState (struct ngadmin *nga, int *s);
+
+
+/**
+ * Set the loop detection state. 
+ * Changes the loop detection state. 
+ * @note You must be logged on a switch. 
+ * @param nga A pointer to the ngadmin structure. 
+ * @param s An integer with value 0 or 1. 
+ * @return ERR_OK when everything is well or an error code otherwise. 
+ **/
+int ngadmin_setLoopDetectionState (struct ngadmin *nga, int s);
+
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/src/ports.c b/lib/src/ports.c
index 8804e4b..99f8b48 100644
--- a/lib/src/ports.c
+++ b/lib/src/ports.c
@@ -184,3 +184,59 @@ int ngadmin_cabletest (struct ngadmin *nga, struct cabletest *ct, int nb)
 }
 
 
+int ngadmin_getLoopDetectionState (struct ngadmin *nga, int *s)
+{
+	List *attr;
+	ListNode *ln;
+	struct attr *at;
+	int ret = ERR_OK;
+	
+	
+	if (nga == NULL || s == NULL)
+		return ERR_INVARG;
+	else if (nga->current == NULL)
+		return ERR_NOTLOG;
+	
+	attr = createEmptyList();
+	pushBackList(attr, newEmptyAttr(ATTR_LOOP_DETECT));
+	ret = readRequest(nga, attr);
+	if (ret != ERR_OK)
+		goto end;
+	
+	filterAttributes(attr, ATTR_LOOP_DETECT, ATTR_END);
+	
+	*s = 0;
+	
+	if (attr->first == NULL) {
+		ret = ERR_BADREPLY;
+		goto end;
+	}
+	at = attr->first->data;
+	if (at->size != 1) {
+		ret = ERR_BADREPLY;
+		goto end;
+	}
+	*s = *(char *)at->data;
+	
+	
+end:
+	destroyList(attr, (void(*)(void*))freeAttr);
+	
+	
+	return ret;
+}
+
+
+int ngadmin_setLoopDetectionState (struct ngadmin *nga, int s)
+{
+	List *attr;
+	
+	
+	attr = createEmptyList();
+	pushBackList(attr, newByteAttr(ATTR_LOOP_DETECT, s != 0));
+	
+	
+	return writeRequest(nga, attr);
+}
+
+
diff --git a/raw/include/nsdp/protocol.h b/raw/include/nsdp/protocol.h
index def40c4..70d111e 100644
--- a/raw/include/nsdp/protocol.h
+++ b/raw/include/nsdp/protocol.h
@@ -66,6 +66,7 @@
 #define ATTR_IGMP_BLOCK_UNK	0x6C00
 #define ATTR_IGMP_VALID_V3	0x7000
 #define ATTR_TLV_BITMAP		0x7400
+#define ATTR_LOOP_DETECT	0x9000
 #define ATTR_END		0xFFFF
 
 
diff --git a/raw/src/attr.c b/raw/src/attr.c
index fca3c32..3d0e4c9 100644
--- a/raw/src/attr.c
+++ b/raw/src/attr.c
@@ -549,6 +549,7 @@ static int processAttr (struct attr *at, bool encode)
 	case ATTR_STORM_ENABLE:
 	case ATTR_IGMP_BLOCK_UNK:
 	case ATTR_IGMP_VALID_V3:
+	case ATTR_LOOP_DETECT:
 		if (at->size != 1)
 			return -EMSGSIZE;
 		
diff --git a/spy/src/spy.c b/spy/src/spy.c
index 7c842cc..69c89fa 100644
--- a/spy/src/spy.c
+++ b/spy/src/spy.c
@@ -267,6 +267,10 @@ static void print_attr (const struct attr *at)
 		printf("\tvalidate IGMPv3 = %s\n", *byte ? "yes" : "no");
 		break;
 	
+	case ATTR_LOOP_DETECT:
+		printf("\tloop detection = %s\n", *byte ? "yes" : "no");
+		break;
+	
 	default:
 		printf("\tunknown\n");
 	}
diff --git a/wireshark/nsdp.lua b/wireshark/nsdp.lua
index 6703a21..08caca8 100644
--- a/wireshark/nsdp.lua
+++ b/wireshark/nsdp.lua
@@ -225,6 +225,7 @@ local attributes = {
 	[0x6C00] = {name = "Block Unknown IGMP Addresses", dissect = "uint"}, 
 	[0x7000] = {name = "Validate IGMPv3 Headers", dissect = "uint"}, 
 	[0x7400] = {name = "TLV Bitmap", dissect = nill}, 
+	[0x9000] = {name = "Loop Detection", dissect = "uint"}, 
 	[0xFFFF] = {name = "End", dissect = nill}
 }