diff --git a/THANKS b/THANKS
index 1302c03..8375381 100644
--- a/THANKS
+++ b/THANKS
@@ -38,3 +38,4 @@ Martijn van Brummelen
 Anton Tkachev
 Derrick Lin
 Ivanov Ivan
+Manuel Hachtkemper
diff --git a/man/dhcpd-pools.1.in b/man/dhcpd-pools.1.in
index df78f84..88794d8 100644
--- a/man/dhcpd-pools.1.in
+++ b/man/dhcpd-pools.1.in
@@ -192,6 +192,12 @@ defined size.  This option is meaningful only in context of alarming, and
 will intented to supress for example single host ranges.  By default this
 option is not in use.
 .TP
+\fB\-p\fR, \fB\-\-perfdata\fR
+Print additional performance data, like lease count, touched leases and
+backup leases.  This option is meaningful only in context of alarming and
+will print lots of data, if there are many networks.  By default this option
+is not in use.
+.TP
 \fB\-v\fR, \fB\-\-version\fR
 Print version information to standard output and exit successfully.
 .TP
diff --git a/src/dhcpd-pools.c b/src/dhcpd-pools.c
index d7f57f0..e3b775a 100644
--- a/src/dhcpd-pools.c
+++ b/src/dhcpd-pools.c
@@ -129,6 +129,7 @@ int main(int argc, char **argv)
 		{"warn-count", required_argument, NULL, OPT_WARN_COUNT},
 		{"crit-count", required_argument, NULL, OPT_CRIT_COUNT},
 		{"minsize", required_argument, NULL, OPT_MINSIZE},
+		{"perfdata", no_argument, NULL, 'p'},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -148,6 +149,7 @@ int main(int argc, char **argv)
 	config.critical = ALARM_CRIT;
 	config.warn_count = 0x100000000;	/* == 2^32 that is the entire IPv4 space */
 	config.crit_count = 0x100000000;	/* basically turns off the count criteria */
+	config.perfdata = false;
 	/* File location defaults */
 	strncpy(config.dhcpdconf_file, DHCPDCONF_FILE, MAXLEN - 1);
 	strncpy(config.dhcpdlease_file, DHCPDLEASE_FILE, MAXLEN - 1);
@@ -165,7 +167,7 @@ int main(int argc, char **argv)
 	while (1) {
 		int c;
 
-		c = getopt_long(argc, argv, "c:l:f:o:s:rL:vh", long_options, &option_index);
+		c = getopt_long(argc, argv, "c:l:f:o:s:rL:pvh", long_options, &option_index);
 		if (c == EOF)
 			break;
 		switch (c) {
@@ -235,6 +237,10 @@ int main(int argc, char **argv)
 		case OPT_MINSIZE:
 			config.minsize = strtod_or_err(optarg, "illegal argument");
 			break;
+		case 'p':
+			/* Print additional performance data in alarming mode */
+			config.perfdata = true;
+			break;
 		case 'v':
 			/* Print version */
 			print_version();
diff --git a/src/dhcpd-pools.h b/src/dhcpd-pools.h
index c20b72f..4415d62 100644
--- a/src/dhcpd-pools.h
+++ b/src/dhcpd-pools.h
@@ -210,6 +210,7 @@ struct configuration_t {
 		backups_found:1,
 		snet_alarms:1,
 		print_mac_addreses:1,
+		perfdata:1,
 		header_limit:3,
 		number_limit:3;
 };
diff --git a/src/other.c b/src/other.c
index cd2cb3a..5e54367 100644
--- a/src/other.c
+++ b/src/other.c
@@ -474,6 +474,7 @@ void __attribute__ ((__noreturn__)) usage(int status)
 	fputs(		"      --crit-count=NR    a number of free leases before critical raised\n", out);
 	fputs(		"      --minsize=size     disable alarms for small ranges and shared-nets\n", out);
 	fputs(		"      --snet-alarms      suppress range alarms that are part of a shared-net\n", out);
+	fputs(		"  -p  --perfdata         print additional perfdata in alarming mode\n", out);
 	fputs(		"  -v, --version          output version information and exit\n", out);
 	fputs(		"  -h, --help             display this help and exit\n", out);
 	fputs(		"\n", out);
diff --git a/src/output.c b/src/output.c
index e220243..35af873 100644
--- a/src/output.c
+++ b/src/output.c
@@ -1014,6 +1014,29 @@ int output_alarming(void)
 		if (ri != 0) {
 			fprintf(outfile, " range_ignored=%d", ri);
 		}
+		if (config.perfdata == 1 && config.number_limit & R_BIT) {
+			for (i = 0; i < num_ranges; i++) {
+				range_p--;
+				range_size = get_range_size(range_p);
+				if (config.minsize < range_size) {
+					fprintf(outfile, " %s_r=",
+						ntop_ipaddr(&range_p->first_ip));
+					fprintf(outfile, "%g;%g;%g;0;%g",
+						range_p->count,
+						(range_size * config.warning / 100),
+						(range_size * config.critical / 100),
+						range_size);
+					fprintf(outfile, " %s_rt=%g",
+						ntop_ipaddr(&range_p->first_ip),
+						range_p->touched);
+					if (config.backups_found == 1) {
+						fprintf(outfile, " %s_rbu=%g",
+							ntop_ipaddr(&range_p->first_ip),
+							range_p->backups);
+					}
+				}
+			}
+		}
 		fprintf(outfile, "\n");
 	} else {
 		fprintf(outfile, " ");
@@ -1025,7 +1048,29 @@ int output_alarming(void)
 		}
 		fprintf(outfile, "; | snet_crit=%d snet_warn=%d snet_ok=%d", sc, sw, so);
 		if (si != 0) {
-			fprintf(outfile, " snet_ignored=%d\n", si);
+			fprintf(outfile, " snet_ignored=%d", si);
+		}
+		if (config.perfdata == 1 && config.header_limit & R_BIT) {
+			for (i = 0; i < num_shared_networks; i++) {
+				if (config.minsize < shared_p->available) {
+					fprintf(outfile, " '%s_s'=%g;%g;%g;0;%g",
+						shared_p->name,
+						shared_p->used,
+						(shared_p->available * config.warning / 100),
+						(shared_p->available * config.critical / 100),
+						shared_p->available);
+					fprintf(outfile, " '%s_st'=%g",
+						shared_p->name,
+						shared_p->touched);
+					if (config.backups_found == 1) {
+						fprintf(outfile, " '%s_sbu'=%g",
+						shared_p->name,
+						shared_p->backups);
+					}
+				}
+				shared_p--;
+			}
+			fprintf(outfile, "\n");
 		}
 	}
 	fprintf(outfile, "\n");
diff --git a/tests/Makemodule.am b/tests/Makemodule.am
index 12d6907..46bac47 100644
--- a/tests/Makemodule.am
+++ b/tests/Makemodule.am
@@ -13,6 +13,7 @@ TESTS = \
 	tests/big-small \
 	tests/bootp \
 	tests/complete \
+	tests/complete-perfdata \
 	tests/empty \
 	tests/full-json \
 	tests/full-xml \
@@ -22,7 +23,8 @@ TESTS = \
 	tests/same-twice \
 	tests/simple \
 	tests/sorts \
-	tests/v6
+	tests/v6 \
+	tests/v6-perfdata
 
 EXTRA_DIST += \
 	tests/confs \
diff --git a/tests/complete-perfdata b/tests/complete-perfdata
new file mode 100755
index 0000000..2765fd4
--- /dev/null
+++ b/tests/complete-perfdata
@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# Minimal regression test suite.
+
+IAM=$(basename $0)
+TESTDATA=${IAM%-*}
+
+if [ ! -d tests/outputs ]; then
+	mkdir tests/outputs
+fi
+
+dhcpd-pools -c $top_srcdir/tests/confs/$TESTDATA \
+	    -l $top_srcdir/tests/leases/$TESTDATA -o tests/outputs/$IAM \
+	    --warning 80 --perfdata
+diff -u $top_srcdir/tests/expected/$IAM tests/outputs/$IAM
+exit $?
diff --git a/tests/expected/alarm-count-option b/tests/expected/alarm-count-option
index 5b00b83..a535df7 100644
--- a/tests/expected/alarm-count-option
+++ b/tests/expected/alarm-count-option
@@ -9,7 +9,6 @@ Shared nets - crit: 1 warn: 0 ok: 1; | snet_crit=1 snet_warn=0 snet_ok=1
 == minsize ==
 OK: Ranges - crit: 0 warn: 0 ok: 0 ignored: 5; | range_crit=0 range_warn=0 range_ok=0 range_ignored=5
 Shared nets - crit: 0 warn: 0 ok: 0 ignored: 2; | snet_crit=0 snet_warn=0 snet_ok=0 snet_ignored=2
-
 0
 == snet alarms ==
 WARNING: dhcpd-pools: Ranges - crit: 0 warn: 0 ok: 0; | range_crit=0 range_warn=0 range_ok=0
diff --git a/tests/expected/complete-perfdata b/tests/expected/complete-perfdata
new file mode 100644
index 0000000..d9219e9
--- /dev/null
+++ b/tests/expected/complete-perfdata
@@ -0,0 +1,3 @@
+OK: Ranges - crit: 0 warn: 0 ok: 5; | range_crit=0 range_warn=0 range_ok=5 10.4.0.1_r=5;16;18;0;20 10.4.0.1_rt=0 10.3.0.1_r=9;16;18;0;20 10.3.0.1_rt=0 10.2.0.1_r=8;16;18;0;20 10.2.0.1_rt=0 10.1.0.1_r=10;16;18;0;20 10.1.0.1_rt=0 10.0.0.1_r=11;16;18;0;20 10.0.0.1_rt=0
+Shared nets - crit: 0 warn: 0 ok: 2; | snet_crit=0 snet_warn=0 snet_ok=2 'example2_s'=17;32;36;0;40 'example2_st'=0 'example1_s'=21;32;36;0;40 'example1_st'=0
+
diff --git a/tests/expected/v6-perfdata b/tests/expected/v6-perfdata
new file mode 100644
index 0000000..50ea786
--- /dev/null
+++ b/tests/expected/v6-perfdata
@@ -0,0 +1,3 @@
+OK: Ranges - crit: 0 warn: 0 ok: 2; | range_crit=0 range_warn=0 range_ok=2 dead:abba:4000::2_r=1;203.2;228.6;0;254 dead:abba:4000::2_rt=0 dead:abba:1000::2_r=2;3.77789e+21;4.25013e+21;0;4.72237e+21 dead:abba:1000::2_rt=1
+Shared nets - crit: 0 warn: 0 ok: 0; | snet_crit=0 snet_warn=0 snet_ok=0
+
diff --git a/tests/v6-perfdata b/tests/v6-perfdata
new file mode 100755
index 0000000..2765fd4
--- /dev/null
+++ b/tests/v6-perfdata
@@ -0,0 +1,16 @@
+#!/bin/sh
+#
+# Minimal regression test suite.
+
+IAM=$(basename $0)
+TESTDATA=${IAM%-*}
+
+if [ ! -d tests/outputs ]; then
+	mkdir tests/outputs
+fi
+
+dhcpd-pools -c $top_srcdir/tests/confs/$TESTDATA \
+	    -l $top_srcdir/tests/leases/$TESTDATA -o tests/outputs/$IAM \
+	    --warning 80 --perfdata
+diff -u $top_srcdir/tests/expected/$IAM tests/outputs/$IAM
+exit $?