diff --git a/clients/Makefile.am b/clients/Makefile.am
index 89669a7992..0ea33105cc 100644
--- a/clients/Makefile.am
+++ b/clients/Makefile.am
@@ -57,7 +57,7 @@ endif
 # object .so names would differ)
 
 # libupsclient version information
-libupsclient_la_LDFLAGS = -version-info 4:0:0
+libupsclient_la_LDFLAGS = -version-info 5:0:0
 
 # libnutclient version information
 libnutclient_la_SOURCES = nutclient.h nutclient.cpp
diff --git a/clients/upsclient.c b/clients/upsclient.c
index b90587b001..dd4c9486ae 100644
--- a/clients/upsclient.c
+++ b/clients/upsclient.c
@@ -442,7 +442,7 @@ static HOST_CERT_t* upscli_find_host_cert(const char* hostname)
 	return NULL;
 }
 
-int upscli_cleanup()
+int upscli_cleanup(void)
 {
 #ifdef WITH_OPENSSL
 	if (ssl_ctx) {
@@ -567,7 +567,7 @@ static int upscli_select_read(const int fd, void *buf, const size_t buflen, cons
 }
 
 /* internal: abstract the SSL calls for the other functions */
-static int net_read(UPSCONN_t *ups, char *buf, size_t buflen)
+static int net_read(UPSCONN_t *ups, char *buf, size_t buflen, unsigned int timeout)
 {
 	int	ret = -1;
 
@@ -587,7 +587,7 @@ static int net_read(UPSCONN_t *ups, char *buf, size_t buflen)
 	}
 #endif
 
-	ret = upscli_select_read(ups->fd, buf, buflen, 5, 0);
+	ret = upscli_select_read(ups->fd, buf, buflen, timeout, 0);
 
 	/* error reading data, server disconnected? */
 	if (ret < 0) {
@@ -628,7 +628,7 @@ static int upscli_select_write(const int fd, const void *buf, const size_t bufle
 }
 
 /* internal: abstract the SSL calls for the other functions */
-static int net_write(UPSCONN_t *ups, const char *buf, size_t buflen)
+static int net_write(UPSCONN_t *ups, const char *buf, size_t buflen, unsigned int timeout)
 {
 	int	ret = -1;
 
@@ -648,7 +648,7 @@ static int net_write(UPSCONN_t *ups, const char *buf, size_t buflen)
 	}
 #endif
 
-	ret = upscli_select_write(ups->fd, buf, buflen, 0, 0);
+	ret = upscli_select_write(ups->fd, buf, buflen, timeout, 0);
 
 	/* error writing data, server disconnected? */
 	if (ret < 0) {
@@ -1326,7 +1326,7 @@ int upscli_list_next(UPSCONN_t *ups, unsigned int numq, const char **query,
 	return 1;
 }
 
-int upscli_sendline(UPSCONN_t *ups, const char *buf, size_t buflen)
+int upscli_sendline_timeout(UPSCONN_t *ups, const char *buf, size_t buflen, unsigned int timeout)
 {
 	int	ret;
 
@@ -1349,7 +1349,7 @@ int upscli_sendline(UPSCONN_t *ups, const char *buf, size_t buflen)
 		return -1;
 	}
 
-	ret = net_write(ups, buf, buflen);
+	ret = net_write(ups, buf, buflen, timeout);
 
 	if (ret < 1) {
 		upscli_disconnect(ups);
@@ -1359,7 +1359,12 @@ int upscli_sendline(UPSCONN_t *ups, const char *buf, size_t buflen)
 	return 0;
 }
 
-int upscli_readline(UPSCONN_t *ups, char *buf, size_t buflen)
+int upscli_sendline(UPSCONN_t *ups, const char *buf, size_t buflen)
+{
+	return upscli_sendline_timeout(ups, buf, buflen, 0);
+}
+
+int upscli_readline_timeout(UPSCONN_t *ups, char *buf, size_t buflen, unsigned int timeout)
 {
 	int	ret;
 	size_t	recv;
@@ -1387,7 +1392,7 @@ int upscli_readline(UPSCONN_t *ups, char *buf, size_t buflen)
 
 		if (ups->readidx == ups->readlen) {
 
-			ret = net_read(ups, ups->readbuf, sizeof(ups->readbuf));
+			ret = net_read(ups, ups->readbuf, sizeof(ups->readbuf), timeout);
 
 			if (ret < 1) {
 				upscli_disconnect(ups);
@@ -1409,6 +1414,11 @@ int upscli_readline(UPSCONN_t *ups, char *buf, size_t buflen)
 	return 0;
 }
 
+int upscli_readline(UPSCONN_t *ups, char *buf, size_t buflen)
+{
+	return upscli_readline_timeout(ups, buf, buflen, DEFAULT_NETWORK_TIMEOUT);
+}
+
 /* split upsname[@hostname[:port]] into separate components */
 int upscli_splitname(const char *buf, char **upsname, char **hostname, int *port)
 {
@@ -1518,7 +1528,7 @@ int upscli_disconnect(UPSCONN_t *ups)
 		return 0;
 	}
 
-	net_write(ups, "LOGOUT\n", 7);
+	net_write(ups, "LOGOUT\n", 7, 0);
 
 #ifdef WITH_OPENSSL
 	if (ups->ssl) {
diff --git a/clients/upsclient.h b/clients/upsclient.h
index ac5fb5d567..d3da201bf1 100644
--- a/clients/upsclient.h
+++ b/clients/upsclient.h
@@ -69,7 +69,7 @@ typedef struct {
 const char *upscli_strerror(UPSCONN_t *ups);
 
 int upscli_init(int certverify, const char *certpath, const char *certname, const char *certpasswd);
-int upscli_cleanup();
+int upscli_cleanup(void);
 
 int upscli_tryconnect(UPSCONN_t *ups, const char *host, int port, int flags, struct timeval *tv);
 int upscli_connect(UPSCONN_t *ups, const char *host, int port, int flags);
@@ -86,8 +86,10 @@ int upscli_list_start(UPSCONN_t *ups, unsigned int numq, const char **query);
 int upscli_list_next(UPSCONN_t *ups, unsigned int numq, const char **query,
 		unsigned int *numa, char ***answer);
 
+int upscli_sendline_timeout(UPSCONN_t *ups, const char *buf, size_t buflen, unsigned int timeout);
 int upscli_sendline(UPSCONN_t *ups, const char *buf, size_t buflen);
 
+int upscli_readline_timeout(UPSCONN_t *ups, char *buf, size_t buflen, unsigned int timeout);
 int upscli_readline(UPSCONN_t *ups, char *buf, size_t buflen);
 
 int upscli_splitname(const char *buf, char **upsname, char **hostname,
diff --git a/clients/upscmd.c b/clients/upscmd.c
index f4990a872c..f8e237d429 100644
--- a/clients/upscmd.c
+++ b/clients/upscmd.c
@@ -1,6 +1,8 @@
 /* upscmd - simple "client" to test instant commands via upsd
 
-   Copyright (C) 2000  Russell Kroll <rkroll@exploits.org>
+   Copyright (C)
+     2000  Russell Kroll <rkroll@exploits.org>
+     2019  EATON (author: Arnaud Quette <ArnaudQuette@eaton.com>)
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -28,8 +30,10 @@
 
 #include "upsclient.h"
 
-static char		*upsname = NULL, *hostname = NULL;
+static char			*upsname = NULL, *hostname = NULL;
 static UPSCONN_t	*ups = NULL;
+static int			tracking_enabled = 0;
+static unsigned int		timeout = DEFAULT_TRACKING_TIMEOUT;
 
 struct list_t {
 	char	*name;
@@ -41,13 +45,16 @@ static void usage(const char *prog)
 	printf("Network UPS Tools upscmd %s\n\n", UPS_VERSION);
 	printf("usage: %s [-h]\n", prog);
 	printf("       %s [-l <ups>]\n", prog);
-	printf("       %s [-u <username>] [-p <password>] <ups> <command> [<value>]\n\n", prog);
+	printf("       %s [-u <username>] [-p <password>] [-w] [-t <timeout>] <ups> <command> [<value>]\n\n", prog);
 	printf("Administration program to initiate instant commands on UPS hardware.\n");
 	printf("\n");
 	printf("  -h		display this help text\n");
 	printf("  -l <ups>	show available commands on UPS <ups>\n");
 	printf("  -u <username>	set username for command authentication\n");
 	printf("  -p <password>	set password for command authentication\n");
+	printf("  -w            wait for the completion of command by the driver\n");
+	printf("                and return its actual result from the device\n");
+	printf("  -t <timeout>	set a timeout when using -w (in seconds, default: %u)\n", DEFAULT_TRACKING_TIMEOUT);
 	printf("\n");
 	printf("  <ups>		UPS identifier - <upsname>[@<hostname>[:<port>]]\n");
 	printf("  <command>	Valid instant command - test.panel.start, etc.\n");
@@ -138,7 +145,10 @@ static void listcmds(void)
 
 static void do_cmd(char **argv, const int argc)
 {
+	int		cmd_complete = 0;
 	char	buf[SMALLBUF];
+	char	tracking_id[UUID4_LEN];
+	time_t	start, now;
 
 	if (argc > 1) {
 		snprintf(buf, sizeof(buf), "INSTCMD %s %s %s\n", upsname, argv[0], argv[1]);
@@ -154,11 +164,49 @@ static void do_cmd(char **argv, const int argc)
 		fatalx(EXIT_FAILURE, "Instant command failed: %s", upscli_strerror(ups));
 	}
 
-	/* FUTURE: status cookies will tie in here */
+	/* verify answer */
 	if (strncmp(buf, "OK", 2) != 0) {
 		fatalx(EXIT_FAILURE, "Unexpected response from upsd: %s", buf);
 	}
 
+	/* check for status tracking id */
+	if (
+		!tracking_enabled ||
+		/* sanity check on the size: "OK TRACKING " + UUID4_LEN */
+		strlen(buf) != (UUID4_LEN - 1 + strlen("OK TRACKING "))
+	) {
+		/* reply as usual */
+		fprintf(stderr, "%s\n", buf);
+		return;
+	}
+
+	snprintf(tracking_id, sizeof(tracking_id), "%s", buf + strlen("OK TRACKING "));
+	time(&start);
+
+	/* send status tracking request, looping if status is PENDING */
+	while (!cmd_complete) {
+
+		/* check for timeout */
+		time(&now);
+		if (difftime(now, start) >= timeout)
+			fatalx(EXIT_FAILURE, "Can't receive status tracking information: timeout");
+
+		snprintf(buf, sizeof(buf), "GET TRACKING %s\n", tracking_id);
+
+		if (upscli_sendline(ups, buf, strlen(buf)) < 0)
+			fatalx(EXIT_FAILURE, "Can't send status tracking request: %s", upscli_strerror(ups));
+
+		/* and get status tracking reply */
+		if (upscli_readline_timeout(ups, buf, sizeof(buf), timeout) < 0)
+			fatalx(EXIT_FAILURE, "Can't receive status tracking information: %s", upscli_strerror(ups));
+
+		if (strncmp(buf, "PENDING", 7))
+			cmd_complete = 1;
+		else
+			/* wait a second before retrying */
+			sleep(1);
+	}
+
 	fprintf(stderr, "%s\n", buf);
 }
 
@@ -180,7 +228,7 @@ int main(int argc, char **argv)
 	char	buf[SMALLBUF], username[SMALLBUF], password[SMALLBUF];
 	const char	*prog = xbasename(argv[0]);
 
-	while ((i = getopt(argc, argv, "+lhu:p:V")) != -1) {
+	while ((i = getopt(argc, argv, "+lhu:p:t:wV")) != -1) {
 
 		switch (i)
 		{
@@ -198,6 +246,15 @@ int main(int argc, char **argv)
 			have_pw = 1;
 			break;
 
+		case 't':
+			if (!str_to_uint(optarg, &timeout, 10))
+				fatal_with_errno(EXIT_FAILURE, "Could not convert the provided value for timeout ('-t' option) to unsigned int");
+			break;
+
+		case 'w':
+			tracking_enabled = 1;
+			break;
+
 		case 'V':
 			fatalx(EXIT_SUCCESS, "Network UPS Tools upscmd %s", UPS_VERSION);
 
@@ -313,6 +370,25 @@ int main(int argc, char **argv)
 		fatalx(EXIT_FAILURE, "Set password failed: %s", upscli_strerror(ups));
 	}
 
+	/* enable status tracking ID */
+	if (tracking_enabled) {
+
+		snprintf(buf, sizeof(buf), "SET TRACKING ON\n");
+
+		if (upscli_sendline(ups, buf, strlen(buf)) < 0) {
+			fatalx(EXIT_FAILURE, "Can't enable command status tracking: %s", upscli_strerror(ups));
+		}
+
+		if (upscli_readline(ups, buf, sizeof(buf)) < 0) {
+			fatalx(EXIT_FAILURE, "Enabling command status tracking failed: %s", upscli_strerror(ups));
+		}
+
+		/* Verify the result */
+		if (strncmp(buf, "OK", 2) != 0) {
+			fatalx(EXIT_FAILURE, "Enabling command status tracking failed. upsd answered: %s", buf);
+		}
+	}
+
 	do_cmd(&argv[1], argc - 1);
 
 	exit(EXIT_SUCCESS);
diff --git a/clients/upsrw.c b/clients/upsrw.c
index dd388e1702..0d1906de51 100644
--- a/clients/upsrw.c
+++ b/clients/upsrw.c
@@ -1,6 +1,8 @@
 /* upsrw - simple client for read/write variable access (formerly upsct2)
 
-   Copyright (C) 1999  Russell Kroll <rkroll@exploits.org>
+   Copyright (C)
+     1999  Russell Kroll <rkroll@exploits.org>
+     2019  EATON (author: Arnaud Quette <ArnaudQuette@eaton.com>)
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -28,8 +30,10 @@
 #include "upsclient.h"
 #include "extstate.h"
 
-static char		*upsname = NULL, *hostname = NULL;
+static char			*upsname = NULL, *hostname = NULL;
 static UPSCONN_t	*ups = NULL;
+static int			tracking_enabled = 0;
+static unsigned int		timeout = DEFAULT_TRACKING_TIMEOUT;
 
 struct list_t {
 	char	*name;
@@ -40,7 +44,7 @@ static void usage(const char *prog)
 {
 	printf("Network UPS Tools %s %s\n\n", prog, UPS_VERSION);
 	printf("usage: %s [-h]\n", prog);
-	printf("       %s [-s <variable>] [-u <username>] [-p <password>] <ups>\n\n", prog);
+	printf("       %s [-s <variable>] [-u <username>] [-p <password>] [-w] [-t <timeout>] <ups>\n\n", prog);
 	printf("Demo program to set variables within UPS hardware.\n");
 	printf("\n");
 	printf("  -h            display this help text\n");
@@ -48,6 +52,9 @@ static void usage(const char *prog)
 	printf("		use -s VAR=VALUE to avoid prompting for value\n");
 	printf("  -u <username> set username for command authentication\n");
 	printf("  -p <password> set password for command authentication\n");
+	printf("  -w            wait for the completion of setting by the driver\n");
+	printf("                and return its actual result from the device\n");
+	printf("  -t <timeout>	set a timeout when using -w (in seconds, default: %u)\n", DEFAULT_TRACKING_TIMEOUT);
 	printf("\n");
 	printf("  <ups>         UPS identifier - <upsname>[@<hostname>[:<port>]]\n");
 	printf("\n");
@@ -67,7 +74,10 @@ static void clean_exit(void)
 
 static void do_set(const char *varname, const char *newval)
 {
+	int		cmd_complete = 0;
 	char	buf[SMALLBUF], enc[SMALLBUF];
+	char	tracking_id[UUID4_LEN];
+	time_t	start, now;
 
 	snprintf(buf, sizeof(buf), "SET VAR %s %s \"%s\"\n", upsname, varname, pconf_encode(newval, enc, sizeof(enc)));
 
@@ -79,11 +89,49 @@ static void do_set(const char *varname, const char *newval)
 		fatalx(EXIT_FAILURE, "Set variable failed: %s", upscli_strerror(ups));
 	}
 
-	/* FUTURE: status cookies will tie in here */
+	/* verify answer */
 	if (strncmp(buf, "OK", 2) != 0) {
 		fatalx(EXIT_FAILURE, "Unexpected response from upsd: %s", buf);
 	}
 
+	/* check for status tracking id */
+	if (
+		!tracking_enabled ||
+		/* sanity check on the size: "OK TRACKING " + UUID4_LEN */
+		strlen(buf) != (UUID4_LEN - 1 + strlen("OK TRACKING "))
+	) {
+		/* reply as usual */
+		fprintf(stderr, "%s\n", buf);
+		return;
+	}
+
+	snprintf(tracking_id, sizeof(tracking_id), "%s", buf + strlen("OK TRACKING "));
+	time(&start);
+
+	/* send status tracking request, looping if status is PENDING */
+	while (!cmd_complete) {
+
+		/* check for timeout */
+		time(&now);
+		if (difftime(now, start) >= timeout)
+			fatalx(EXIT_FAILURE, "Can't receive status tracking information: timeout");
+
+		snprintf(buf, sizeof(buf), "GET TRACKING %s\n", tracking_id);
+
+		if (upscli_sendline(ups, buf, strlen(buf)) < 0)
+			fatalx(EXIT_FAILURE, "Can't send status tracking request: %s", upscli_strerror(ups));
+
+		/* and get status tracking reply */
+		if (upscli_readline_timeout(ups, buf, sizeof(buf), timeout) < 0)
+			fatalx(EXIT_FAILURE, "Can't receive status tracking information: %s", upscli_strerror(ups));
+
+		if (strncmp(buf, "PENDING", 7))
+			cmd_complete = 1;
+		else
+			/* wait a second before retrying */
+			sleep(1);
+	}
+
 	fprintf(stderr, "%s\n", buf);
 }
 
@@ -178,6 +226,25 @@ static void do_setvar(const char *varname, char *uin, const char *pass)
 		fatalx(EXIT_FAILURE, "Error: old variable names are not supported");
 	}
 
+	/* enable status tracking ID */
+	if (tracking_enabled) {
+
+		snprintf(temp, sizeof(temp), "SET TRACKING ON\n");
+
+		if (upscli_sendline(ups, temp, strlen(temp)) < 0) {
+			fatalx(EXIT_FAILURE, "Can't enable set variable status tracking: %s", upscli_strerror(ups));
+		}
+
+		if (upscli_readline(ups, temp, sizeof(temp)) < 0) {
+			fatalx(EXIT_FAILURE, "Enabling set variable status tracking failed: %s", upscli_strerror(ups));
+		}
+
+		/* Verify the result */
+		if (strncmp(temp, "OK", 2) != 0) {
+			fatalx(EXIT_FAILURE, "Enabling set variable status tracking failed. upsd answered: %s", temp);
+		}
+	}
+
 	do_set(varname, newval);
 }
 
@@ -369,7 +436,7 @@ static void do_type(const char *varname)
 	ret = upscli_get(ups, numq, query, &numa, &answer);
 
 	if ((ret < 0) || (numa < numq)) {
-		printf("Unknown type\n");	
+		printf("Unknown type\n");
 		return;
 	}
 
@@ -519,7 +586,7 @@ int main(int argc, char **argv)
 	const char	*prog = xbasename(argv[0]);
 	char	*password = NULL, *username = NULL, *setvar = NULL;
 
-	while ((i = getopt(argc, argv, "+hs:p:u:V")) != -1) {
+	while ((i = getopt(argc, argv, "+hs:p:t:u:wV")) != -1) {
 		switch (i)
 		{
 		case 's':
@@ -528,9 +595,16 @@ int main(int argc, char **argv)
 		case 'p':
 			password = optarg;
 			break;
+		case 't':
+			if (!str_to_uint(optarg, &timeout, 10))
+				fatal_with_errno(EXIT_FAILURE, "Could not convert the provided value for timeout ('-t' option) to unsigned int");
+			break;
 		case 'u':
 			username = optarg;
 			break;
+		case 'w':
+			tracking_enabled = 1;
+			break;
 		case 'V':
 			printf("Network UPS Tools %s %s\n", prog, UPS_VERSION);
 			exit(EXIT_SUCCESS);
diff --git a/common/snprintf.c b/common/snprintf.c
index 62c8c14182..be7785266f 100644
--- a/common/snprintf.c
+++ b/common/snprintf.c
@@ -54,7 +54,7 @@
 #include "config.h"
 
 #include <string.h>
-# include <ctype.h>
+#include <ctype.h>
 #include <sys/types.h>
 
 #if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)
diff --git a/conf/upsd.conf.sample b/conf/upsd.conf.sample
index e7328f6865..5cb94062ce 100644
--- a/conf/upsd.conf.sample
+++ b/conf/upsd.conf.sample
@@ -21,6 +21,14 @@
 # the data fresh within the normal 15 second interval.  Watch the syslog
 # for notifications from upsd about staleness.
 
+# =======================================================================
+# TRACKINGDELAY <seconds>
+# TRACKINGDELAY 3600
+#
+# This defaults to 1 hour. When instant commands and variables setting status
+# tracking is enabled, status execution information are kept during this
+# amount of time, and then cleaned up.
+
 # =======================================================================
 # STATEPATH <path>
 # STATEPATH /var/run/nut
diff --git a/docs/man/Makefile.am b/docs/man/Makefile.am
index 0c0646bcd6..fef33f6db0 100644
--- a/docs/man/Makefile.am
+++ b/docs/man/Makefile.am
@@ -252,7 +252,9 @@ MAN3_DEV_PAGES = \
 	upscli_list_next.3 \
 	upscli_list_start.3 \
 	upscli_readline.3 \
+	upscli_readline_timeout.3 \
 	upscli_sendline.3 \
+	upscli_sendline_timeout.3 \
 	upscli_splitaddr.3 \
 	upscli_splitname.3 \
 	upscli_ssl.3 \
@@ -289,6 +291,12 @@ MAN3_DEV_PAGES = \
 	nutscan_get_serial_ports_list.3 \
 	nutscan_init.3
 
+upscli_readline_timeout.3: upscli_readline.3
+	touch $@
+
+upscli_sendline_timeout.3: upscli_sendline.3
+	touch $@
+
 MAN1_DEV_PAGES = \
 	libupsclient-config.1
 endif
diff --git a/docs/man/upscli_cleanup.txt b/docs/man/upscli_cleanup.txt
index cd88a518e1..611c3de051 100644
--- a/docs/man/upscli_cleanup.txt
+++ b/docs/man/upscli_cleanup.txt
@@ -11,7 +11,7 @@ SYNOPSIS
 
  #include <upsclient.h>
 
- int upscli_cleanup();
+ int upscli_cleanup(void);
 
 DESCRIPTION
 -----------
diff --git a/docs/man/upscli_readline.txt b/docs/man/upscli_readline.txt
index 52106ade43..06db9c62c3 100644
--- a/docs/man/upscli_readline.txt
+++ b/docs/man/upscli_readline.txt
@@ -4,7 +4,7 @@ UPSCLI_READLINE(3)
 NAME
 ----
 
-upscli_readline - read a single response from a UPS
+upscli_readline, upscli_readline_timeout - read a single response from a UPS
 
 SYNOPSIS
 --------
@@ -12,23 +12,28 @@ SYNOPSIS
  #include <upsclient.h>
 
  int upscli_readline(UPSCONN_t *ups, char *buf, size_t buflen);
+ int upscli_readline_timeout(UPSCONN_t *ups, char *buf, size_t buflen, unsigned int timeout);
 
 DESCRIPTION
 -----------
-The *upscli_readline()* function takes the pointer 'ups' to a
-`UPSCONN_t` state structure, receives a single line from the server, and
-copies up to 'buflen' bytes of the response into the buffer
-'buf'.
+The *upscli_readline()* and *upscli_readline_timeout()* functions take the
+pointer 'ups' to a `UPSCONN_t` state structure, receive a single line from the
+server, and copy up to 'buflen' bytes of the response into the buffer 'buf'.
 
 Some parsing of the string occurs during reception.  In particular,
 ERR messages from linkman:upsd[8] are detected and will cause this
 function to return -1.
 
+The difference between the two functions is that *upscli_readline_timeout()*
+lets the caller decide the amount of time ('timeout' seconds) after which it
+should give up and return, whereas *upscli_readline()* does not offer this
+freedom, and uses NUT default network timeout (5 seconds).
+
 RETURN VALUE
 ------------
 
-The *upscli_readline()* function returns 0 on success, or -1 if an
-error occurs.
+The *upscli_readline()* and *upscli_readline_timeout()* functions return 0 on
+success, or -1 if an error occurs.
 
 SEE ALSO
 --------
diff --git a/docs/man/upscli_sendline.txt b/docs/man/upscli_sendline.txt
index c449c6dd5d..cefa264538 100644
--- a/docs/man/upscli_sendline.txt
+++ b/docs/man/upscli_sendline.txt
@@ -4,7 +4,7 @@ UPSCLI_SENDLINE(3)
 NAME
 ----
 
-upscli_sendline - send a single command to a UPS
+upscli_sendline, upscli_sendline_timeout - send a single command to a UPS
 
 SYNOPSIS
 --------
@@ -13,22 +13,28 @@ SYNOPSIS
  #include <upsclient.h>
 
  int upscli_sendline(UPSCONN_t *ups, const char *buf, size_t buflen);
+ int upscli_sendline_timeout(UPSCONN_t *ups, const char *buf, size_t buflen, unsigned int timeout);
 
 DESCRIPTION
 -----------
 
-The *upscli_sendline()* function takes the pointer 'ups' to a
-`UPSCONN_t` state structure and transmits a buffer 'buf' of size
-'buflen' to the server. 
+The *upscli_sendline()* and *upscli_sendline_timeout()* functions take the
+pointer 'ups' to a `UPSCONN_t` state structure and transmit a buffer 'buf' of
+size 'buflen' to the server.
 
 The data in 'buf' must be a fully formatted protocol command as no
 parsing of the buffer occurs within this function.
 
+The difference between the two functions is that *upscli_sendline_timeout()*
+lets the caller decide the amount of time ('timeout' seconds) after which it
+should give up and return, whereas *upscli_sendline()* does not offer this
+freedom, and uses an immediate timeout (0 second).
+
 RETURN VALUE
 ------------
 
-The *upscli_sendline()* function returns 0 on success, or -1 if an
-error occurs.
+The *upscli_sendline()* and *upscli_sendline_timeout()* functions return 0 on
+success, or -1 if an error occurs.
 
 SEE ALSO
 --------
diff --git a/docs/man/upscmd.txt b/docs/man/upscmd.txt
index 8083fece02..a66d0f1399 100644
--- a/docs/man/upscmd.txt
+++ b/docs/man/upscmd.txt
@@ -11,7 +11,7 @@ SYNOPSIS
 
 *upscmd* -l 'ups'
 
-*upscmd* [-u 'username'] [-p 'password'] 'ups' 'command'
+*upscmd* [-u 'username'] [-p 'password'] [-w] [-t <timeout>] 'ups' 'command'
 
 DESCRIPTION
 -----------
@@ -42,6 +42,17 @@ you will be prompted for this when invoking a command if -u is not used.
 Set the password to authenticate to the server.  This is also optional 
 like -u, and you will be prompted for it if necessary.
 
+*-w*::
+Wait for the completion of command execution by the driver and return its
+actual result from the device. Note that this feature requires that both upsd
+and the driver support TRACKING (NUT version 2.7.5 or higher) or it will
+otherwise fail.
+The command will also block until an actual result is provided from the driver,
+or the timeout is reached (see *-t*).
+
+*-t* 'seconds'::
+Set a timeout when using *-w*. Defaults to 10 seconds.
+
 'ups'::
 Connect to this UPS.  The format is `upsname[@hostname[:port]]`.  The default
 hostname is "localhost".
@@ -84,8 +95,7 @@ BUGS
 ----
 
 There is currently no way to tell the user when the driver requires
-confirmation to invoke a command such as `load.off`.  Similarly, there is
-not yet a way to tell the user if a command succeeds or fails.
+confirmation to invoke a command such as `load.off`.
 
 This is on the list of things to fix in the future, so don't despair.
 It involves magic cookies.
diff --git a/docs/man/upsd.conf.txt b/docs/man/upsd.conf.txt
index ebdfef6024..5947792f20 100644
--- a/docs/man/upsd.conf.txt
+++ b/docs/man/upsd.conf.txt
@@ -26,6 +26,12 @@ to make upsd wait longer.
 +
 Most users should leave this at the default value.
 
+"TRACKINGDELAY 'seconds'"::
+
+When instant commands and variables setting status tracking is enabled, status
+execution information are kept during this amount of time, and then cleaned up.
+This defaults to 3600 (1 hour).
+
 "STATEPATH 'path'"::
 
 Tell upsd to look for the driver state sockets in 'path' rather
diff --git a/docs/man/upsrw.txt b/docs/man/upsrw.txt
index 8053364104..eb4ed351f8 100644
--- a/docs/man/upsrw.txt
+++ b/docs/man/upsrw.txt
@@ -13,7 +13,7 @@ SYNOPSIS
 
 *upsrw* -h
 
-*upsrw* -s 'variable' [-u 'username'] [-p 'password'] 'ups'
+*upsrw* -s 'variable' [-u 'username'] [-p 'password'] [-w] [-t <timeout>] 'ups'
 
 DESCRIPTION
 -----------
@@ -58,6 +58,17 @@ linkman:upsd.users[5], and are not linked to system usernames.
 Set the password to authenticate to the server.  This is also optional
 like -u, and you will be prompted for it if necessary.  
 
+*-w*::
+Wait for the completion of setting execution by the driver and return its
+actual result from the device. Note that this feature requires that both upsd
+and the driver support TRACKING (NUT version 2.7.5 or higher) or it will
+otherwise fail.
+The command will also block until an actual result is provided from the driver,
+or the timeout is reached (see *-t*).
+
+*-t* 'seconds'::
+Set a timeout when using *-w*. Defaults to 10 seconds.
+
 'ups'::
 View or change the settings on this UPS.  The format for this option is
 `upsname[@hostname[:port]]`.  The default hostname is "localhost".
diff --git a/docs/net-protocol.txt b/docs/net-protocol.txt
index 4f9a7fa34d..91c62dbdc4 100644
--- a/docs/net-protocol.txt
+++ b/docs/net-protocol.txt
@@ -44,6 +44,8 @@ NUT network protocol, over the time:
 |1.1              |>= 1.5.0    |Original protocol (without old commands)
 .2+|1.2        .2+|>= 2.6.4    |Add "LIST CLIENTS" and "NETVER" commands
                                |Add ranges of values for writable variables
+.2+|1.3        .2+|>= 2.7.5    |Add "cmdparam" to "INSTCMD"
+                               |Add "TRACKING" commands (GET, SET)
 |===============================================================================
 
 NOTE: any new version of the protocol implies an update of NUT_NETVERSION
@@ -189,6 +191,26 @@ This is like DESC above, but it applies to the instant commands.
 This replaces the old "INSTCMDDESC" command.
 
 
+TRACKING
+~~~~~~~~
+
+Form:
+
+	GET TRACKING      (activation status of TRACKING)
+	GET TRACKING <id> (execution status of a command / setvar)
+	GET TRACKING 1bd31808-cb49-4aec-9d75-d056e6f018d2
+
+Response:
+
+	ON                   (TRACKING feature is enabled)
+	OFF                  (TRACKING feature is disabled)
+	PENDING              (command execution is pending)
+	SUCCESS              (command was successfully executed)
+	ERR UNKNOWN          (command execution failed with unknown error)
+	ERR INVALID-ARGUMENT (command execution failed due to missing or invalid argument)
+	ERR FAILED           (command execution failed)
+
+
 LIST
 ----
 
@@ -377,22 +399,54 @@ Response:
 SET
 ---
 
+VAR
+~~~
+
 Form:
 
 	SET VAR <upsname> <varname> "<value>"
 	SET VAR su700 ups.id "My UPS"
 
+Response:
+
+	OK                         (if TRACKING is not enabled)
+	OK TRACKING <id>           (if TRACKING is enabled)
+	ERR <message> [<extra>...] (see Error responses)
+
+
+TRACKING
+~~~~~~~~
+
+Form:
+
+	SET TRACKING <value>
+	SET TRACKING ON
+	SET TRACKING OFF
+
+Response:
+
+	OK
+	ERR INVALID-ARGUMENT  (if <value> is not "ON" or "OFF")
+	ERR USERNAME-REQUIRED (if not yet authenticated)
+	ERR PASSWORD-REQUIRED (if not yet authenticated)
+
 
 INSTCMD
 -------
 
 Form:
 
-	INSTCMD <upsname> <cmdname> [cmdparam]
+	INSTCMD <upsname> <cmdname> [<cmdparam>]
 	INSTCMD su700 test.panel.start
 	INSTCMD su700 load.off.delay 120
 
-NOTE: cmdparam is an additional and optional parameter for the command.
+NOTE: <cmdparam> is an additional and optional parameter for the command.
+
+Response:
+
+	OK                         (if TRACKING is not enabled)
+	OK TRACKING <id>           (if TRACKING is enabled)
+	ERR <message> [<extra>...] (see Error responses)
 
 
 LOGOUT
@@ -699,13 +753,6 @@ For example, "LIST VARS <ups> +DESC" would return the current value
 like now, but it would also append the description of that variable.
 
 
-Command status
-~~~~~~~~~~~~~~
-
-After sending an INSTCMD or SET, a client will eventually be able to
-poll to see whether it was completed successfully by the driver.
-
-
 Get collection
 ~~~~~~~~~~~~~~
 
diff --git a/docs/nut-names.txt b/docs/nut-names.txt
index bdc30b8d06..c5eb47cb3d 100644
--- a/docs/nut-names.txt
+++ b/docs/nut-names.txt
@@ -621,46 +621,43 @@ Instant commands
 ----------------
 
 [options="header"]
-|===============================================================================
-| Name                      | Description
-| load.off                  | Turn off the load immediately
-| load.on                   | Turn on the load immediately
-| load.off.delay            | Turn off the load possibly after a delay
-| load.on.delay             | Turn on the load possibly after a delay
-| shutdown.return           | Turn off the load possibly after a delay
+|========================================================================
+| Name                     | Description
+| load.off                 | Turn off the load immediately
+| load.on                  | Turn on the load immediately
+| load.off.delay           | Turn off the load possibly after a delay
+| load.on.delay            | Turn on the load possibly after a delay
+| shutdown.return          | Turn off the load possibly after a delay
                              and return when power is back
-| shutdown.stayoff          | Turn off the load possibly after a delay
-                              and remain off even if power returns
-| shutdown.stop             | Stop a shutdown in progress
-| shutdown.reboot           | Shut down the load briefly while rebooting the UPS
-| shutdown.reboot.graceful  | After a delay, shut down the load briefly
-                              while rebooting the UPS
-| test.panel.start          | Start testing the UPS panel
-| test.panel.stop           | Stop a UPS panel test
-| test.failure.start        | Start a simulated power failure
-| test.failure.stop         | Stop simulating a power failure
-| test.battery.start        | Start a battery test
-| test.battery.start.quick  | Start a "quick" battery test
-| test.battery.start.deep   | Start a "deep" battery test
-| test.battery.stop         | Stop the battery test
-| test.system.start         | Start a system test
-| calibrate.start           | Start runtime calibration
-| calibrate.stop            | Stop runtime calibration
-| bypass.start              | Put the UPS in bypass mode
-| bypass.stop               | Take the UPS out of bypass mode
-| reset.input.minmax        | Reset minimum and maximum input voltage status
-| reset.watchdog            | Reset watchdog timer (forced reboot of load)
-| beeper.enable             | Enable UPS beeper/buzzer
-| beeper.disable            | Disable UPS beeper/buzzer
-| beeper.mute               | Temporarily mute UPS beeper/buzzer
-| beeper.toggle             | Toggle UPS beeper/buzzer
-| outlet.n.shutdown.return  | Turn off the outlet possibly after a delay
-                              and return when power is back
-| outlet.n.load.off         | Turn off the outlet immediately
-| outlet.n.load.on          | Turn on the outlet immediately
-| outlet.n.load.cycle       | Power cycle the outlet immediately
-| outlet.n.load.off.delay   | Turn off the outlet possibly after a delay
-| outlet.n.load.on.delay    | Turn on the outlet possibly after a delay
-| outlet.n.load.cycle.delay | Power cycle the outlet possibly after a delay
-| outlet.n.shutdown.return  | Turn off the outlet and return when power is back
-|===============================================================================
+| shutdown.stayoff         | Turn off the load possibly after a delay
+                             and remain off even if power returns
+| shutdown.stop            | Stop a shutdown in progress
+| shutdown.reboot          | Shut down the load briefly while rebooting the UPS
+| shutdown.reboot.graceful | After a delay, shut down the load briefly
+                             while rebooting the UPS
+| test.panel.start         | Start testing the UPS panel
+| test.panel.stop          | Stop a UPS panel test
+| test.failure.start       | Start a simulated power failure
+| test.failure.stop        | Stop simulating a power failure
+| test.battery.start       | Start a battery test
+| test.battery.start.quick | Start a "quick" battery test
+| test.battery.start.deep  | Start a "deep" battery test
+| test.battery.stop        | Stop the battery test
+| test.system.start        | Start a system test
+| calibrate.start          | Start runtime calibration
+| calibrate.stop           | Stop runtime calibration
+| bypass.start             | Put the UPS in bypass mode
+| bypass.stop              | Take the UPS out of bypass mode
+| reset.input.minmax       | Reset minimum and maximum input voltage status
+| reset.watchdog           | Reset watchdog timer (forced reboot of load)
+| beeper.enable            | Enable UPS beeper/buzzer
+| beeper.disable           | Disable UPS beeper/buzzer
+| beeper.mute              | Temporarily mute UPS beeper/buzzer
+| beeper.toggle            | Toggle UPS beeper/buzzer
+| outlet.n.shutdown.return | Turn off the outlet possibly after a delay 
+                             and return when power is back
+| outlet.n.load.off        | Turn off the outlet immediately
+| outlet.n.load.on         | Turn on the outlet immediately
+| outlet.n.load.cycle      | Power cycle the outlet immediately
+| outlet.n.shutdown.return | Turn off the outlet and return when power is back
+|========================================================================
diff --git a/docs/nut.dict b/docs/nut.dict
index 111b886fe3..db8f027385 100644
--- a/docs/nut.dict
+++ b/docs/nut.dict
@@ -1,4 +1,4 @@
-personal_ws-1.1 en 2434 utf-8
+personal_ws-1.1 en 2440 utf-8
 AAS
 ACFAIL
 ACFREQ
@@ -12,6 +12,7 @@ ADDRINFO
 ADK
 ADKK
 AEC
+aec
 AEG
 AES
 AGM
@@ -136,6 +137,7 @@ ByPass
 CA's
 CABAC
 CAs
+cb
 CBLimit
 CCC
 CCCC
@@ -203,6 +205,7 @@ DDDDD
 DDF
 DEADTIME
 DEBUGOUT
+dedb
 DELCMD
 DELENUM
 DELINFO
@@ -999,6 +1002,7 @@ TIOCMBIC
 TIOCMBIS
 TLS
 TODO
+TRACKINGDELAY
 TRYSSL
 TSR
 TST
@@ -2318,6 +2322,7 @@ upserror
 upsfetch
 upsgone
 upsh
+upshandler
 upsidentmodel
 upsimage
 upsload
diff --git a/docs/sock-protocol.txt b/docs/sock-protocol.txt
index 944d3ef7fd..f951aae6d0 100644
--- a/docs/sock-protocol.txt
+++ b/docs/sock-protocol.txt
@@ -146,6 +146,18 @@ status information once this has been sent.
 This will be sent in the beginning of a dump if the data is stale, and
 may be repeated.  It is cleared by DATAOK.
 
+TRACKING
+~~~~~~~~
+
+	TRACKING <id> <value>
+
+This is sent in response to an INSTCMD or SET VAR that includes a TRACKING,
+upon completion of request execution by the driver. <value> is the integer
+return value from the driver handlers instcmd and setvar (see
+drivers/upshandler.h). The server is in charge of translating these codes into
+strings, as per docs/net-protocol.txt GET TRACKING.
+
+
 Commands sent by the server
 ---------------------------
 
@@ -166,16 +178,30 @@ server must not be passed on to the clients when this happens.
 INSTCMD
 ~~~~~~~
 
-	INSTCMD <cmdname>
+	INSTCMD <cmdname> [<cmdparam>] [TRACKING <id>]
 
 	INSTCMD panel.test.start
+	INSTCMD load.off 10
+	INSTCMD load.on 10 TRACKING 1bd31808-cb49-4aec-9d75-d056e6f018d2
+
+NOTE:
+* <cmdparam> is an additional and optional parameter for the command,
+* "TRACKING <id>" can be provided to track commands execution status, if
+TRACKING was set to ON on upsd. In this case, driver will later return
+the execution status, using TRACKING.
 
 SET
 ~~~
 
-	SET <varname> "<value>"
+	SET <varname> "<value>" [TRACKING <id>]
 
 	SET ups.id "Data room"
+	SET ups.id "Data room" TRACKING 2dedb58a-3b91-4fab-831f-c8af4b90760a
+
+NOTE:
+* "TRACKING <id>" can be provided to track commands execution status, if
+TRACKING was set to ON on upsd. In this case, driver will later return
+the execution status, using TRACKING.
 
 DUMPALL
 ~~~~~~~
diff --git a/drivers/dstate.c b/drivers/dstate.c
index 276da18b63..51e41a052a 100644
--- a/drivers/dstate.c
+++ b/drivers/dstate.c
@@ -201,6 +201,7 @@ static int send_to_one(conn_t *conn, const char *fmt, ...)
 	ret = vsnprintf(buf, sizeof(buf), fmt, ap);
 	va_end(ap);
 
+	upsdebugx(2, "%s: sending %.*s", __func__, (int)strcspn(buf, "\n"), buf);
 	if (ret < 1) {
 		upsdebugx(2, "%s: nothing to write", __func__);
 		return 1;
@@ -356,6 +357,12 @@ static int cmd_dump_conn(conn_t *conn)
 	return 1;
 }
 
+
+static void send_tracking(conn_t *conn, const char *id, int value)
+{
+	send_to_one(conn, "TRACKING %s %i\n", id, value);
+}
+
 static int sock_arg(conn_t *conn, int numarg, char **arg)
 {
 	if (numarg < 1) {
@@ -394,20 +401,40 @@ static int sock_arg(conn_t *conn, int numarg, char **arg)
 		return 0;
 	}
 
-	/* INSTCMD <cmdname> [<value>]*/
+	/* INSTCMD <cmdname> [<cmdparam>] [TRACKING <id>] */
 	if (!strcasecmp(arg[0], "INSTCMD")) {
+		int ret;
+		char *cmdname = arg[1];
+		char *cmdparam = NULL;
+		char *cmdid = NULL;
+
+		/* Check if <cmdparam> and TRACKING were provided */
+		if (numarg == 3) {
+			cmdparam = arg[2];
+		} else if (numarg == 4 && !strcasecmp(arg[2], "TRACKING")) {
+			cmdid = arg[3];
+		} else if (numarg == 5 && !strcasecmp(arg[3], "TRACKING")) {
+			cmdparam = arg[2];
+			cmdid = arg[4];
+		} else if (numarg != 2) {
+			upslogx(LOG_NOTICE, "Malformed INSTCMD request");
+			return 0;
+		}
+
+		if (cmdid)
+			upsdebugx(3, "%s: TRACKING = %s", __func__, cmdid);
 
 		/* try the new handler first if present */
 		if (upsh.instcmd) {
-			if (numarg > 2) {
-				upsh.instcmd(arg[1], arg[2]);
-				return 1;
-			}
+			ret = upsh.instcmd(cmdname, cmdparam);
 
-			upsh.instcmd(arg[1], NULL);
+			/* send back execution result */
+			if (cmdid)
+				send_tracking(conn, cmdid, ret);
+
+			/* The command was handled, status is a separate consideration */
 			return 1;
 		}
-
 		upslogx(LOG_NOTICE, "Got INSTCMD, but driver lacks a handler");
 		return 1;
 	}
@@ -416,12 +443,33 @@ static int sock_arg(conn_t *conn, int numarg, char **arg)
 		return 0;
 	}
 
-	/* SET <var> <value> */
+	/* SET <var> <value> [TRACKING <id>] */
 	if (!strcasecmp(arg[0], "SET")) {
+		int ret;
+		char *setid = NULL;
+
+		/* Check if TRACKING was provided */
+		if (numarg == 5) {
+			if (!strcasecmp(arg[3], "TRACKING")) {
+				setid = arg[4];
+			}
+			else {
+				upslogx(LOG_NOTICE, "Got SET <var> with unsupported parameters (%s/%s)",
+					arg[3], arg[4]);
+				return 0;
+			}
+			upsdebugx(3, "%s: TRACKING = %s", __func__, setid);
+		}
 
 		/* try the new handler first if present */
 		if (upsh.setvar) {
-			upsh.setvar(arg[1], arg[2]);
+			ret = upsh.setvar(arg[1], arg[2]);
+
+			/* send back execution result */
+			if (setid)
+				send_tracking(conn, setid, ret);
+
+			/* The command was handled, status is a separate consideration */
 			return 1;
 		}
 
diff --git a/drivers/upshandler.h b/drivers/upshandler.h
index ca9a349594..fea10bc20c 100644
--- a/drivers/upshandler.h
+++ b/drivers/upshandler.h
@@ -25,15 +25,15 @@ enum {
 	STAT_INSTCMD_HANDLED = 0,	/* completed successfully */
 	STAT_INSTCMD_UNKNOWN,		/* unspecified error */
 	STAT_INSTCMD_INVALID,		/* invalid command */
-	STAT_INSTCMD_FAILED			/* command failed */
+	STAT_INSTCMD_FAILED		/* command failed */
 };
 
 /* return values for setvar */
 enum {
 	STAT_SET_HANDLED = 0,	/* completed successfully */
-	STAT_SET_UNKNOWN,		/* unspecified error */
-	STAT_SET_INVALID,		/* not writeable */
-	STAT_SET_FAILED			/* writing failed */
+	STAT_SET_UNKNOWN,	/* unspecified error */
+	STAT_SET_INVALID,	/* not writeable */
+	STAT_SET_FAILED		/* writing failed */
 };
 
 /* structure for funcs that get called by msg parse routine */
diff --git a/include/common.h b/include/common.h
index b1fb53ed2d..248dadd374 100644
--- a/include/common.h
+++ b/include/common.h
@@ -53,6 +53,12 @@ extern "C" {
 
 extern const char *UPS_VERSION;
 
+/** @brief Default timeout (in seconds) for network operations, as used by `upsclient` and `nut-scanner`. */
+#define DEFAULT_NETWORK_TIMEOUT		5
+
+/** @brief Default timeout (in seconds) for retrieving the result of a `TRACKING`-enabled operation (e.g. `INSTCMD`, `SET VAR`). */
+#define DEFAULT_TRACKING_TIMEOUT	10
+
 /* get the syslog ready for us */
 void open_syslog(const char *progname);
 
@@ -128,6 +134,9 @@ char * get_libname(const char* base_libname);
 #define SMALLBUF	512
 #define LARGEBUF	1024
 
+/** @brief (Minimum) Size that a string must have to hold a UUID4 (i.e. UUID4 length + the terminating null character). */
+#define UUID4_LEN	37
+
 /* Provide declarations for getopt() global variables */
 
 #ifdef NEED_GETOPT_H
diff --git a/scripts/augeas/nutupsdconf.aug.in b/scripts/augeas/nutupsdconf.aug.in
index d3aef1d300..4c200039e8 100644
--- a/scripts/augeas/nutupsdconf.aug.in
+++ b/scripts/augeas/nutupsdconf.aug.in
@@ -39,6 +39,7 @@ let comment  = Util.comment
 let path     = word
 
 let upsd_maxage    = [ opt_spc . key "MAXAGE"    . sep_spc . store num  . eol ]
+let upsd_trackingdelay = [ opt_spc . key "TRACKINGDELAY"    . sep_spc . store num  . eol ]
 let upsd_statepath = [ opt_spc . key "STATEPATH" . sep_spc . store path . eol ]
 let upsd_listen    = [ opt_spc . key "LISTEN"    . sep_spc 
                           . [ label "interface" . store ip ]
@@ -49,13 +50,14 @@ let upsd_certfile = [ opt_spc . key "CERTFILE" . sep_spc . store path . eol ]
 
 (************************************************************************
  * MAXAGE seconds
+ * TRACKINGDELAY seconds
  * STATEPATH path
  * LISTEN interface port
  *    Multiple LISTEN addresses may be specified. The default is to bind to 0.0.0.0 if no LISTEN addresses are specified.
  *    LISTEN 127.0.0.1 LISTEN 192.168.50.1 LISTEN ::1 LISTEN 2001:0db8:1234:08d3:1319:8a2e:0370:7344
  *
  *************************************************************************)
-let upsd_other  =  upsd_maxage | upsd_statepath | upsd_listen_list | upsd_maxconn | upsd_certfile
+let upsd_other  =  upsd_maxage | upsd_trackingdelay | upsd_statepath | upsd_listen_list | upsd_maxconn | upsd_certfile
 
 let upsd_lns    = (upsd_other|comment|empty)*
 
diff --git a/scripts/augeas/tests/test_nut.aug b/scripts/augeas/tests/test_nut.aug
index 4153ed7cf5..eb79b07bd3 100644
--- a/scripts/augeas/tests/test_nut.aug
+++ b/scripts/augeas/tests/test_nut.aug
@@ -27,6 +27,7 @@ test NutUpsConf.ups_lns get ups_conf =
 
 let upsd_conf = "
 MAXAGE 30
+TRACKINGDELAY 600
 LISTEN 0.0.0.0 3493
 MAXCONN 1024
 "
@@ -34,6 +35,7 @@ MAXCONN 1024
 test NutUpsdConf.upsd_lns get upsd_conf = 
 	{ }
 	{ "MAXAGE"      = "30" }
+	{ "TRACKINGDELAY" = "600" }
 	{ "LISTEN"
 		{ "interface" = "0.0.0.0" }
 		{ "port"     = "3493"     } }
diff --git a/server/conf.c b/server/conf.c
index aea8220cd7..e6046ed7c9 100644
--- a/server/conf.c
+++ b/server/conf.c
@@ -23,6 +23,7 @@
 #include "sstate.h"
 #include "user.h"
 #include "netssl.h"
+#include <ctype.h>
 
 	ups_t	*upstable = NULL;
 	int	num_ups = 0;
@@ -121,14 +122,38 @@ static int parse_upsd_conf_args(int numargs, char **arg)
 
 	/* MAXAGE <seconds> */
 	if (!strcmp(arg[0], "MAXAGE")) {
-		maxage = atoi(arg[1]);
-		return 1;
+		if (isdigit(arg[1])) {
+			maxage = atoi(arg[1]);
+			return 1;
+		}
+		else {
+			upslogx(LOG_ERR, "MAXAGE has non numeric value (%s)!", arg[1]);
+			return 0;
+		}
+	}
+
+	/* TRACKINGDELAY <seconds> */
+	if (!strcmp(arg[0], "TRACKINGDELAY")) {
+		if (isdigit(arg[1])) {
+			tracking_delay = atoi(arg[1]);
+			return 1;
+		}
+		else {
+			upslogx(LOG_ERR, "TRACKINGDELAY has non numeric value (%s)!", arg[1]);
+			return 0;
+		}
 	}
 
 	/* MAXCONN <connections> */
 	if (!strcmp(arg[0], "MAXCONN")) {
-		maxconn = atoi(arg[1]);
-		return 1;
+		if (isdigit(arg[1])) {
+			maxconn = atoi(arg[1]);
+			return 1;
+		}
+		else {
+			upslogx(LOG_ERR, "MAXCONN has non numeric value (%s)!", arg[1]);
+			return 0;
+		}
 	}
 
 	/* STATEPATH <dir> */
@@ -162,8 +187,14 @@ static int parse_upsd_conf_args(int numargs, char **arg)
 #ifdef WITH_CLIENT_CERTIFICATE_VALIDATION
 	/* CERTREQUEST (0 | 1 | 2) */
 	if (!strcmp(arg[0], "CERTREQUEST")) {
-		certrequest = atoi(arg[1]);
-		return 1;
+		if (isdigit(arg[1])) {
+			certrequest = atoi(arg[1]);
+			return 1;
+		}
+		else {
+			upslogx(LOG_ERR, "CERTREQUEST has non numeric value (%s)!", arg[1]);
+			return 0;
+		}
 	}
 #endif /* WITH_CLIENT_CERTIFICATE_VALIDATION */
 #endif /* WITH_OPENSSL | WITH_NSS */
diff --git a/server/netget.c b/server/netget.c
index 5ab41c3f3a..55a27a429c 100644
--- a/server/netget.c
+++ b/server/netget.c
@@ -216,6 +216,25 @@ static void get_var(nut_ctype_t *client, const char *upsname, const char *var)
 
 void net_get(nut_ctype_t *client, int numarg, const char **arg)
 {
+	if (numarg < 1) {
+		send_err(client, NUT_ERR_INVALID_ARGUMENT);
+		return;
+	}
+
+	/* GET TRACKING [ID] */
+	if (!strcasecmp(arg[0], "TRACKING")) {
+		if (numarg < 2) {
+			sendback(client, "%s\n", (client->tracking) ? "ON" : "OFF");
+		}
+		else {
+			if (client->tracking)
+				sendback(client, "%s\n", tracking_get(arg[1]));
+			else
+				send_err(client, NUT_ERR_FEATURE_NOT_CONFIGURED);
+		}
+		return;
+	}
+
 	if (numarg < 2) {
 		send_err(client, NUT_ERR_INVALID_ARGUMENT);
 		return;
diff --git a/server/netinstcmd.c b/server/netinstcmd.c
index c21d7ec1d7..3c4ccc8212 100644
--- a/server/netinstcmd.c
+++ b/server/netinstcmd.c
@@ -29,9 +29,9 @@
 #include "netinstcmd.h"
 
 static void send_instcmd(nut_ctype_t *client, const char *upsname, 
-	const char *cmdname, const char *value)
+	const char *cmdname, const char *value, const char *tracking_id)
 {
-	int	found;
+	int	found, have_tracking_id = 0;
 	upstype_t	*ups;
 	const	cmdlist_t  *ctmp;
 	char	sockcmd[SMALLBUF], esc[SMALLBUF];
@@ -70,20 +70,30 @@ static void send_instcmd(nut_ctype_t *client, const char *upsname,
 		return;
 	}
 
-	/* see if the user has also passed a value for this command */
-	if (value != NULL) {
-		upslogx(LOG_INFO, "Instant command: %s@%s did %s with value \"%s\" on %s",
-			client->username, client->addr, cmdname, value, ups->name);
+	/* Format the base command */
+	snprintf(sockcmd, sizeof(sockcmd), "INSTCMD %s", cmdname);
 
-		snprintf(sockcmd, sizeof(sockcmd), "INSTCMD %s %s\n",
-			cmdname, pconf_encode(value, esc, sizeof(esc)));
+	/* see if the user has also passed a value for this command */
+	if (value != NULL)
+		snprintfcat(sockcmd, sizeof(sockcmd), " %s", pconf_encode(value, esc, sizeof(esc)));
+
+	/* see if the user want execution tracking for this command */
+	if (tracking_id && *tracking_id) {
+		snprintfcat(sockcmd, sizeof(sockcmd), " TRACKING %s", tracking_id);
+		/* Add an entry in the tracking structure */
+		tracking_add(tracking_id);
+		have_tracking_id = 1;
 	}
-	else  {
-		upslogx(LOG_INFO, "Instant command: %s@%s did %s on %s",
-			client->username, client->addr, cmdname, ups->name);
 
-		snprintf(sockcmd, sizeof(sockcmd), "INSTCMD %s\n", cmdname);
-	}
+	/* add EOL */
+	snprintfcat(sockcmd, sizeof(sockcmd), "\n");
+
+	upslogx(LOG_INFO, "Instant command: %s@%s did %s%s%s on %s (tracking ID: %s)",
+		client->username, client->addr, cmdname,
+		(value != NULL)?" with value ":"",
+		(value != NULL)?value:"",
+		ups->name,
+		(have_tracking_id) ? tracking_id : "disabled");
 
 	if (!sstate_sendline(ups, sockcmd)) {
 		upslogx(LOG_INFO, "Set command send failed");
@@ -91,18 +101,38 @@ static void send_instcmd(nut_ctype_t *client, const char *upsname,
 		return;
 	}
 
-	/* FIXME: need to retrieve the cookie number */
-	sendback(client, "OK\n");
+	/* return the result, possibly including tracking_id */
+	if (have_tracking_id)
+		sendback(client, "OK TRACKING %s\n", tracking_id);
+	else
+		sendback(client, "OK\n");
 }
 
 void net_instcmd(nut_ctype_t *client, int numarg, const char **arg)
 {
+	const char *devname = NULL;
+	const char *cmdname = NULL;
+	const char *cmdparam = NULL;
+	char	tracking_id[UUID4_LEN] = "";
+
 	if (numarg < 2) {
 		send_err(client, NUT_ERR_INVALID_ARGUMENT);
 		return;
 	}
-	
-	/* INSTCMD <ups> <cmdname> [<extra>]*/
-	send_instcmd(client, arg[0], arg[1], (numarg == 3)?arg[2]:NULL);
+
+	/* INSTCMD <ups> <cmdname> [cmdparam] */
+	/* Check arguments */
+	devname = arg[0];
+	cmdname = arg[1];
+	if (numarg == 3)
+		cmdparam = arg[2];
+
+	if (client->tracking) {
+		/* Generate a tracking ID, if client requested status tracking */
+		nut_uuid_v4(tracking_id);
+	}
+
+	send_instcmd(client, devname, cmdname, cmdparam, tracking_id);
+
 	return;
 }
diff --git a/server/netset.c b/server/netset.c
index b88bb40f7d..a69aa96ff4 100644
--- a/server/netset.c
+++ b/server/netset.c
@@ -28,13 +28,14 @@
 #include "netset.h"
 
 static void set_var(nut_ctype_t *client, const char *upsname, const char *var,
-	const char *newval)
+	const char *newval, const char *tracking_id)
 {
 	upstype_t	*ups;
 	const	char	*val;
 	const	enum_t  *etmp;
 	const	range_t  *rtmp;
 	char	cmd[SMALLBUF], esc[SMALLBUF];
+	int	have_tracking_id = 0;
 
 	ups = get_ups_ptr(upsname);
 
@@ -134,31 +135,88 @@ static void set_var(nut_ctype_t *client, const char *upsname, const char *var,
 
 	/* must be OK now */
 
-	upslogx(LOG_INFO, "Set variable: %s@%s set %s on %s to %s",
-		client->username, client->addr, var, ups->name, newval);
-
-	snprintf(cmd, sizeof(cmd), "SET %s \"%s\"\n",
+	snprintf(cmd, sizeof(cmd), "SET %s \"%s\"",
 		var, pconf_encode(newval, esc, sizeof(esc)));
 
+	/* see if the user want execution tracking for this command */
+	if (tracking_id && *tracking_id) {
+		snprintfcat(cmd, sizeof(cmd), " TRACKING %s", tracking_id);
+		/* Add an entry in the tracking structure */
+		tracking_add(tracking_id);
+		have_tracking_id = 1;
+	}
+
+	/* add EOL */
+	snprintfcat(cmd, sizeof(cmd), "\n");
+
+	upslogx(LOG_INFO, "Set variable: %s@%s set %s on %s to %s (tracking ID: %s)",
+		client->username, client->addr, var, ups->name, newval,
+		(have_tracking_id) ? tracking_id : "disabled");
+
 	if (!sstate_sendline(ups, cmd)) {
 		upslogx(LOG_INFO, "Set command send failed");
 		send_err(client, NUT_ERR_SET_FAILED);
 		return;
 	}
 
-	sendback(client, "OK\n");
+	/* return the result, possibly including tracking_id */
+	if (have_tracking_id)
+		sendback(client, "OK TRACKING %s\n", tracking_id);
+	else
+		sendback(client, "OK\n");
 }
 
 void net_set(nut_ctype_t *client, int numarg, const char **arg)
 {
-	if (numarg < 4) {
+	char	tracking_id[UUID4_LEN] = "";
+
+	/* Base verification, to ensure that we have at least the SET parameter */
+	if (numarg < 2) {
 		send_err(client, NUT_ERR_INVALID_ARGUMENT);
 		return;
 	}
 
 	/* SET VAR UPS VARNAME VALUE */
 	if (!strcasecmp(arg[0], "VAR")) {
-		set_var(client, arg[1], arg[2], arg[3]);
+		if (numarg < 4) {
+			send_err(client, NUT_ERR_INVALID_ARGUMENT);
+			return;
+		}
+
+		if (client->tracking) {
+			/* Generate a tracking ID, if client requested status tracking */
+			nut_uuid_v4(tracking_id);
+		}
+
+		set_var(client, arg[1], arg[2], arg[3], tracking_id);
+
+		return;
+	}
+
+	/* SET TRACKING VALUE */
+	if (!strcasecmp(arg[0], "TRACKING")) {
+		if (!strcasecmp(arg[1], "ON")) {
+			/* general enablement along with for this client */
+			client->tracking = tracking_enable();
+		}
+		else if (!strcasecmp(arg[1], "OFF")) {
+			/* disable status tracking for this client first */
+			client->tracking = 0;
+			/* then only disable the general one if no other clients use it!
+			 * Note: don't call tracking_free() since we want info to
+			 * persist, and tracking_cleanup() takes care of cleaning */
+			tracking_disable();
+		}
+		else {
+			send_err(client, NUT_ERR_INVALID_ARGUMENT);
+			return;
+		}
+		upsdebugx(1, "%s: TRACKING general %s, client %s.", __func__,
+			tracking_is_enabled() ? "enabled" : "disabled",
+			client->tracking ? "enabled" : "disabled");
+
+		sendback(client, "OK\n");
+
 		return;
 	}
 
diff --git a/server/nut_ctype.h b/server/nut_ctype.h
index c2302aadb8..54184d2baa 100644
--- a/server/nut_ctype.h
+++ b/server/nut_ctype.h
@@ -45,6 +45,9 @@ typedef struct nut_ctype_s {
 	char	*loginups;
 	char	*password;
 	char	*username;
+	/* per client status info for commands and settings
+	 * (disabled by default) */
+	int	tracking;
 
 #ifdef	WITH_OPENSSL
 	SSL	*ssl;
diff --git a/server/sstate.c b/server/sstate.c
index 34e1b2de9a..0365cd30f6 100644
--- a/server/sstate.c
+++ b/server/sstate.c
@@ -25,6 +25,7 @@
 #include "timehead.h"
 
 #include "sstate.h"
+#include "upsd.h"
 #include "upstype.h"
 
 #include <fcntl.h>
@@ -116,6 +117,18 @@ static int parse_args(upstype_t *ups, int numargs, char **arg)
 		return 1;
 	}
 
+	/* TRACKING <id> <status> */
+	if (!strcasecmp(arg[0], "TRACKING")) {
+		tracking_set(arg[1], arg[2]);
+		upsdebugx(1, "TRACKING: ID %s status %s", arg[1], arg[2]);
+
+		/* log actual result of instcmd / setvar */
+		if (strncmp(arg[2], "PENDING", 7) != 0) {
+			upslogx(LOG_INFO, "tracking ID: %s\tresult: %s", arg[1], tracking_get(arg[1]));
+		}
+		return 1;
+	}
+
 	if (numargs < 4)
 		return 0;
 
@@ -388,7 +401,7 @@ int sstate_sendline(upstype_t *ups, const char *buf)
 	ret = write(ups->sock_fd, buf, strlen(buf));
 
 	if (ret == (int)strlen(buf)) {
-		return 1;	
+		return 1;
 	}
 
 	upslog_with_errno(LOG_NOTICE, "Send to UPS [%s] failed", ups->name);
diff --git a/server/upsd.c b/server/upsd.c
index a490608b2d..a49b51110f 100644
--- a/server/upsd.c
+++ b/server/upsd.c
@@ -4,6 +4,7 @@
 	1999		Russell Kroll <rkroll@exploits.org>
 	2008		Arjen de Korte <adkorte-guest@alioth.debian.org>
 	2011 - 2012	Arnaud Quette <arnaud.quette.free.fr>
+	2019 		Eaton (author: Arnaud Quette <ArnaudQuette@eaton.com>)
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -53,6 +54,9 @@ int	deny_severity = LOG_WARNING;
 	/* default 15 seconds before data is marked stale */
 	int	maxage = 15;
 
+	/* default to 1h before cleaning up status tracking entries */
+	int	tracking_delay = 3600;
+
 	/* preloaded to {OPEN_MAX} in main, can be overridden via upsd.conf */
 	int	maxconn = 0;
 
@@ -84,6 +88,28 @@ typedef struct {
 	void		*data;
 } handler_t;
 
+
+/* Commands and settings status tracking */
+
+/* general enable/disable status info for commands and settings
+ * (disabled by default)
+ * Note that only client that requested it will have it enabled
+ * (see nut_ctype.h) */
+static int	tracking_enabled = 0;
+
+/* Commands and settings status tracking structure */
+typedef struct tracking_s {
+	char	*id;
+	int	status;
+	time_t	request_time; /* for cleanup */
+	/* doubly linked list */
+	struct tracking_s	*prev;
+	struct tracking_s	*next;
+} tracking_t;
+
+static tracking_t	*tracking_list = NULL;
+
+
 	/* pollfd  */
 static struct pollfd	*fds = NULL;
 static handler_t	*handler = NULL;
@@ -94,6 +120,11 @@ static char	pidfn[SMALLBUF];
 	/* set by signal handlers */
 static int	reload_flag = 0, exit_flag = 0;
 
+/* Minimalistic support for UUID v4 */
+/* Ref: RFC 4122 https://tools.ietf.org/html/rfc4122#section-4.1.2 */
+#define UUID4_BYTESIZE 16
+
+
 static const char *inet_ntopW (struct sockaddr_storage *s)
 {
 	static char str[40];
@@ -480,6 +511,8 @@ static void client_connect(stype_t *server)
 
 	client->addr = xstrdup(inet_ntopW(&csock));
 
+	client->tracking = 0;
+
 	pconf_init(&client->ctx, NULL);
 
 	if (firstclient) {
@@ -644,6 +677,7 @@ static void upsd_cleanup(void)
 	server_free();
 	client_free();
 	driver_free();
+	tracking_free();
 
 	free(statepath);
 	free(datapath);
@@ -672,6 +706,219 @@ void poll_reload(void)
 	handler = xrealloc(handler, maxconn * sizeof(*handler));
 }
 
+/* instant command and setvar status tracking */
+
+/* allocate a new status tracking entry */
+int tracking_add(const char *id)
+{
+	tracking_t	*item;
+
+	if ((!tracking_enabled) || (!id))
+		return 0;
+
+	item = xcalloc(1, sizeof(*item));
+
+	item->id = xstrdup(id);
+	item->status = STAT_PENDING;
+	time(&item->request_time);
+
+	if (tracking_list) {
+		tracking_list->prev = item;
+		item->next = tracking_list;
+	}
+
+	tracking_list = item;
+
+	return 1;
+}
+
+/* set status of a specific tracking entry */
+int tracking_set(const char *id, const char *value)
+{
+	tracking_t	*item, *next_item;
+
+	/* sanity checks */
+	if ((!tracking_list) || (!id) || (!value))
+		return 0;
+
+	for (item = tracking_list; item; item = next_item) {
+
+		next_item = item->next;
+
+		if (!strcasecmp(item->id, id)) {
+			item->status = atoi(value);
+			return 1;
+		}
+	}
+
+	return 0; /* id not found! */
+}
+
+/* free a specific tracking entry */
+int tracking_del(const char *id)
+{
+	tracking_t	*item, *next_item;
+
+	/* sanity check */
+	if ((!tracking_list) || (!id))
+		return 0;
+
+	upsdebugx(3, "%s: deleting id %s", __func__, id);
+
+	for (item = tracking_list; item; item = next_item) {
+
+		next_item = item->next;
+
+		if (strcasecmp(item->id, id))
+			continue;
+
+		if (item->prev)
+			item->prev->next = item->next;
+		else
+			/* deleting first entry */
+			tracking_list = item->next;
+
+		if (item->next)
+			item->next->prev = item->prev;
+
+		free(item->id);
+		free(item);
+
+		return 1;
+
+	}
+
+	return 0; /* id not found! */
+}
+
+/* free all status tracking entries */
+void tracking_free(void)
+{
+	tracking_t	*item, *next_item;
+
+	/* sanity check */
+	if (!tracking_list)
+		return;
+
+	upsdebugx(3, "%s", __func__);
+
+	for (item = tracking_list; item; item = next_item) {
+		next_item = item->next;
+		tracking_del(item->id);
+	}
+}
+
+/* cleanup status tracking entries according to their age and tracking_delay */
+void tracking_cleanup(void)
+{
+	tracking_t	*item, *next_item;
+	time_t	now;
+
+	/* sanity check */
+	if (!tracking_list)
+		return;
+
+	time(&now);
+
+	upsdebugx(3, "%s", __func__);
+
+	for (item = tracking_list; item; item = next_item) {
+
+		next_item = item->next;
+
+		if (difftime(now, item->request_time) > tracking_delay) {
+			tracking_del(item->id);
+		}
+	}
+}
+
+/* get status of a specific tracking entry */
+char *tracking_get(const char *id)
+{
+	tracking_t	*item, *next_item;
+
+	/* sanity checks */
+	if ((!tracking_list) || (!id))
+		return "ERR UNKNOWN";
+
+	for (item = tracking_list; item; item = next_item) {
+
+		next_item = item->next;
+
+		if (strcasecmp(item->id, id))
+			continue;
+
+		switch (item->status)
+		{
+		case STAT_PENDING:
+			return "PENDING";
+		case STAT_HANDLED:
+			return "SUCCESS";
+		case STAT_UNKNOWN:
+			return "ERR UNKNOWN";
+		case STAT_INVALID:
+			return "ERR INVALID-ARGUMENT";
+		case STAT_FAILED:
+			return "ERR FAILED";
+		}
+	}
+
+	return "ERR UNKNOWN"; /* id not found! */
+}
+
+/* enable general status tracking (tracking_enabled) and return its value (1). */
+int tracking_enable(void)
+{
+	tracking_enabled = 1;
+
+	return tracking_enabled;
+}
+
+/* disable general status tracking only if no client use it anymore.
+ * return the new value for tracking_enabled */
+int tracking_disable(void)
+{
+	nut_ctype_t		*client, *cnext;
+
+	for (client = firstclient; client; client = cnext) {
+		cnext = client->next;
+		if (client->tracking == 1)
+			return 1;
+	}
+	return 0;
+}
+
+/* return current general status of tracking (tracking_enabled). */
+int tracking_is_enabled(void)
+{
+	return tracking_enabled;
+}
+
+/* UUID v4 basic implementation
+ * Note: 'dest' must be at least `UUID4_LEN` long */
+int nut_uuid_v4(char *uuid_str)
+{
+	size_t		i;
+	uint8_t nut_uuid[UUID4_BYTESIZE];
+
+	if (!uuid_str)
+		return 0;
+
+	for (i = 0; i < UUID4_BYTESIZE; i++)
+		nut_uuid[i] = (unsigned)rand() + (unsigned)rand();
+
+	/* set variant and version */
+	nut_uuid[6] = (nut_uuid[6] & 0x0F) | 0x40;
+	nut_uuid[8] = (nut_uuid[8] & 0x3F) | 0x80;
+
+	return snprintf(uuid_str, UUID4_LEN,
+		"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+		nut_uuid[0], nut_uuid[1], nut_uuid[2], nut_uuid[3],
+		nut_uuid[4], nut_uuid[5], nut_uuid[6], nut_uuid[7],
+		nut_uuid[8], nut_uuid[9], nut_uuid[10], nut_uuid[11],
+		nut_uuid[12], nut_uuid[13], nut_uuid[14], nut_uuid[15]);
+}
+
 /* service requests and check on new data */
 static void mainloop(void)
 {
@@ -690,6 +937,9 @@ static void mainloop(void)
 		reload_flag = 0;
 	}
 
+	/* cleanup instcmd/setvar status tracking entries if needed */
+	tracking_cleanup();
+
 	/* scan through driver sockets */
 	for (ups = firstups; ups && (nfds < maxconn); ups = ups->next) {
 
@@ -722,6 +972,7 @@ static void mainloop(void)
 
 		if (difftime(now, client->last_heard) > 60) {
 			/* shed clients after 1 minute of inactivity */
+			/* FIXME: create an upsd.conf parameter (CLIENT_INACTIVITY_DELAY) */
 			client_disconnect(client);
 			continue;
 		}
diff --git a/server/upsd.h b/server/upsd.h
index 2b3a3a74d1..2cd3eb399e 100644
--- a/server/upsd.h
+++ b/server/upsd.h
@@ -68,9 +68,30 @@ void server_free(void);
 
 void check_perms(const char *fn);
 
+/* return values for instcmd / setvar status tracking,
+ * mapped on drivers/upshandler.h, apart from STAT_PENDING (initial state) */
+enum {
+   STAT_PENDING = -1,	/* not yet completed */
+   STAT_HANDLED = 0,	/* completed successfully (NUT_SUCCESS or "OK") */
+   STAT_UNKNOWN,	/* unspecified error (NUT_ERR_UNKNOWN) */
+   STAT_INVALID,	/* invalid command/setvar (NUT_ERR_INVALID_ARGUMENT) */
+   STAT_FAILED		/* command/setvar failed (NUT_ERR_INSTCMD_FAILED / NUT_ERR_SET_FAILED) */
+};
+
+/* Commands and settings status tracking functions */
+int tracking_add(const char *id);
+int tracking_set(const char *id, const char *value);
+int tracking_del(const char *id);
+void tracking_free(void);
+void tracking_cleanup(void);
+char *tracking_get(const char *id);
+int tracking_enable(void);
+int tracking_disable(void);
+int tracking_is_enabled(void);
+
 /* declarations from upsd.c */
 
-extern int		maxage, maxconn;
+extern int		maxage, maxconn, tracking_delay;
 extern char		*statepath, *datapath;
 extern upstype_t	*firstups;
 extern nut_ctype_t	*firstclient;
@@ -91,6 +112,10 @@ extern nut_ctype_t	*firstclient;
 #define shutdown_how 2
 #endif
 
+/* UUID v4 generation function
+ * Note: 'dest' must be at least `UUID4_LEN` long */
+int nut_uuid_v4(char *uuid_str);
+
 #ifdef __cplusplus
 /* *INDENT-OFF* */
 }
diff --git a/tools/nut-scanner/nut-scanner.c b/tools/nut-scanner/nut-scanner.c
index 8b41a3dbf9..25e39d9875 100644
--- a/tools/nut-scanner/nut-scanner.c
+++ b/tools/nut-scanner/nut-scanner.c
@@ -38,8 +38,6 @@
 
 #include "nut-scan.h"
 
-#define DEFAULT_TIMEOUT 5
-
 #define ERR_BAD_OPTION	(-1)
 
 const char optstring[] = "?ht:s:e:E:c:l:u:W:X:w:x:p:b:B:d:L:CUSMOAm:NPqIVaD";
@@ -84,7 +82,7 @@ const struct option longopts[] =
 
 static nutscan_device_t *dev[TYPE_END];
 
-static long timeout = DEFAULT_TIMEOUT*1000*1000; /* in usec */
+static long timeout = DEFAULT_NETWORK_TIMEOUT * 1000 * 1000; /* in usec */
 static char * start_ip = NULL;
 static char * end_ip = NULL;
 static char * port = NULL;
@@ -169,7 +167,7 @@ void show_usage()
 	printf("  -E, --eaton_serial <serial ports list>: Scan serial Eaton devices (XCP, SHUT and Q1).\n");
 
 	printf("\nNetwork specific options:\n");
-	printf("  -t, --timeout <timeout in seconds>: network operation timeout (default %d).\n",DEFAULT_TIMEOUT);
+	printf("  -t, --timeout <timeout in seconds>: network operation timeout (default %d).\n", DEFAULT_NETWORK_TIMEOUT);
 	printf("  -s, --start_ip <IP address>: First IP address to scan.\n");
 	printf("  -e, --end_ip <IP address>: Last IP address to scan.\n");
 	printf("  -m, --mask_cidr <IP address/mask>: Give a range of IP using CIDR notation.\n");
@@ -270,8 +268,8 @@ int main(int argc, char *argv[])
 			case 't':
 				timeout = atol(optarg)*1000*1000; /*in usec*/
 				if( timeout == 0 ) {
-					fprintf(stderr,"Illegal timeout value, using default %ds\n", DEFAULT_TIMEOUT);
-					timeout = DEFAULT_TIMEOUT*1000*1000;
+					fprintf(stderr,"Illegal timeout value, using default %ds\n", DEFAULT_NETWORK_TIMEOUT);
+					timeout = DEFAULT_NETWORK_TIMEOUT * 1000 * 1000;
 				}
 				break;
 			case 's':