diff --git a/Makefile.in b/Makefile.in
index 58258af..9626325 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -129,6 +129,9 @@ install: chronyd chronyc chrony.txt
 %.s : %.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) -S $<
 
+check :
+	cd test/simulation; ./run
+
 install-docs : docs
 	[ -d $(DESTDIR)$(DOCDIR) ] || mkdir -p $(DESTDIR)$(DOCDIR)
 	cp chrony.txt $(DESTDIR)$(DOCDIR)/chrony.txt
diff --git a/test/simulation/001-defaults b/test/simulation/001-defaults
new file mode 100755
index 0000000..466d43b
--- /dev/null
+++ b/test/simulation/001-defaults
@@ -0,0 +1,13 @@
+#!/bin/bash
+
+. test.common
+
+test_start "default test settings"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/002-largenetwork b/test/simulation/002-largenetwork
new file mode 100755
index 0000000..62885e5
--- /dev/null
+++ b/test/simulation/002-largenetwork
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large network"
+
+time_rms_limit=5e-4
+
+server_strata=3
+servers=4
+clients=5
+
+client_start=2000
+min_sync_time=2100
+max_sync_time=2300
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/003-largefreqoffset b/test/simulation/003-largefreqoffset
new file mode 100755
index 0000000..e463f0e
--- /dev/null
+++ b/test/simulation/003-largefreqoffset
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large frequency offset"
+
+max_sync_time=1000
+
+for freq_offset in -5e-2 -5e-3 5e-3 5e-2; do
+	# Adjust offset so it's close to 0 on first clock update
+	time_offset=$(awk "BEGIN {print -($freq_offset * 130)}")
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/004-largetimeoffset b/test/simulation/004-largetimeoffset
new file mode 100755
index 0000000..273056c
--- /dev/null
+++ b/test/simulation/004-largetimeoffset
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large time offset"
+
+min_sync_time=1300
+max_sync_time=1400
+
+for time_offset in -1e2 1e2; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/005-externalstep b/test/simulation/005-externalstep
new file mode 100755
index 0000000..3f26324
--- /dev/null
+++ b/test/simulation/005-externalstep
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. test.common
+
+test_start "external time step"
+
+min_sync_time=1300
+max_sync_time=1500
+
+for step in -1e2 1e2; do
+	# Make one step in 150th second
+	client_step="(* $step (equal 0.1 (sum 1.0) 150))"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/006-largejitter b/test/simulation/006-largejitter
new file mode 100755
index 0000000..50d5db9
--- /dev/null
+++ b/test/simulation/006-largejitter
@@ -0,0 +1,21 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large jitter"
+
+time_offset=1e0
+jitter=1e-1
+
+time_max_limit=5e-1
+freq_max_limit=2e-1
+time_rms_limit=1e-1
+freq_rms_limit=5e-3
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/007-largewander b/test/simulation/007-largewander
new file mode 100755
index 0000000..22ffece
--- /dev/null
+++ b/test/simulation/007-largewander
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+. test.common
+
+test_start "large wander"
+
+wander=1e-7
+
+time_max_limit=5e-3
+freq_max_limit=5e-3
+time_rms_limit=1e-3
+freq_rms_limit=1e-4
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/101-poll b/test/simulation/101-poll
new file mode 100755
index 0000000..ce9bd76
--- /dev/null
+++ b/test/simulation/101-poll
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+. test.common
+test_start "minpoll/maxpoll options"
+
+wander=0.0
+jitter=1e-6
+
+time_max_limit=1e-5
+freq_max_limit=1e-5
+time_rms_limit=5e-6
+freq_rms_limit=5e-6
+client_conf="makestep 1e-2 1"
+
+for poll in $(seq 2 14); do
+	client_server_options="minpoll $poll maxpoll $poll"
+	limit=$[2**$poll * 10]
+	min_sync_time=$[2**$poll * 2]
+	max_sync_time=$[2**$poll * 21 / 10 + 1]
+
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/102-iburst b/test/simulation/102-iburst
new file mode 100755
index 0000000..dd66339
--- /dev/null
+++ b/test/simulation/102-iburst
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+. test.common
+test_start "iburst option"
+
+freq_offset=1e-4
+
+client_conf="makestep 1e-2 1
+driftfile tmp/drift"
+client_server_options="iburst"
+
+min_sync_time=4
+max_sync_time=6
+
+echo "100 1.0" > tmp/drift
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_packet_interval || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/103-initstepslew b/test/simulation/103-initstepslew
new file mode 100755
index 0000000..89611f7
--- /dev/null
+++ b/test/simulation/103-initstepslew
@@ -0,0 +1,32 @@
+#!/bin/bash
+
+. test.common
+test_start "initstepslew directive"
+
+freq_offset=0.0
+wander=0.0
+limit=100
+
+# clknetsim requires source port (if bound) to match dest port
+client_server_options="port 124"
+client_conf="initstepslew 5 192.168.123.1
+port 124"
+
+min_sync_time=15
+max_sync_time=30
+
+for time_offset in -2.0 -0.2 0.2 2.0; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=1
+max_sync_time=1
+
+for time_offset in -1e8 -1e2 1e2 1e8; do
+	run_test || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/104-driftfile b/test/simulation/104-driftfile
new file mode 100755
index 0000000..b65452d
--- /dev/null
+++ b/test/simulation/104-driftfile
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+. test.common
+test_start "driftfile directive"
+
+servers=0
+time_offset=0.0
+wander=0.0
+limit=10
+freq_max_limit=1e-9
+min_sync_time=1
+max_sync_time=1
+client_conf="driftfile tmp/drift"
+
+for freq_offset in -5e-2 -5e-4 -5e-6 5e-6 5e-4 5e-2; do
+	awk "BEGIN {printf \"%.9e 1\", 1e6 - 1 / (1 + $freq_offset) * 1e6}" > tmp/drift
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/105-ntpauth b/test/simulation/105-ntpauth
new file mode 100755
index 0000000..3e88d92
--- /dev/null
+++ b/test/simulation/105-ntpauth
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+. test.common
+
+test_start "NTP authentication"
+
+server_conf="keyfile tmp/keys"
+client_conf="keyfile tmp/keys"
+
+cat > tmp/keys <<-EOF
+1 $(tr -c -d 'a-zA-Z0-9' < /dev/urandom 2> /dev/null | head -c 24)
+2 ASCII:$(tr -c -d 'a-zA-Z0-9' < /dev/urandom 2> /dev/null | head -c 24)
+3 MD5 ASCII:$(tr -c -d 'a-zA-Z' < /dev/urandom 2> /dev/null | head -c 24)
+4 MD5 HEX:$(tr -c -d '0-9A-F' < /dev/urandom 2> /dev/null | head -c 32)
+EOF
+
+for key in 1 2 3 4; do
+	client_server_options="key $key"
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+server_conf=""
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+# This check must fail as server doesn't know the key
+check_sync && test_fail
+
+test_pass
diff --git a/test/simulation/106-refclock b/test/simulation/106-refclock
new file mode 100755
index 0000000..ed04406
--- /dev/null
+++ b/test/simulation/106-refclock
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+. test.common
+test_start "SHM refclock"
+
+servers=0
+limit=1000
+refclock_jitter=$jitter
+min_sync_time=60
+max_sync_time=80
+client_conf="refclock SHM 0"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/107-allowdeny b/test/simulation/107-allowdeny
new file mode 100755
index 0000000..7b16312
--- /dev/null
+++ b/test/simulation/107-allowdeny
@@ -0,0 +1,46 @@
+#!/bin/bash
+
+. test.common
+
+test_start "allow/deny directives"
+
+limit=500
+
+# Note that start_client in clknetsim.bash always adds allow to the config
+
+for server_conf in \
+	"deny" \
+	"deny all" \
+	"deny 192.168.0.0/16" \
+	"deny 192.168.123" \
+	"deny 192.168.123.2" \
+	"deny all
+allow 192.168.124.0/24"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	# These checks are expected to fail
+	check_source_selection && test_fail
+	check_packet_interval && test_fail
+	check_sync && test_fail
+done
+
+for server_conf in \
+	"deny all
+allow" \
+	"deny all
+allow all" \
+	"deny all
+allow 192.168.123" \
+	"deny all
+allow 192.168.123/24" \
+	"deny 192.168.124.0/24"
+do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_packet_interval || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/108-peer b/test/simulation/108-peer
new file mode 100755
index 0000000..b4d21d2
--- /dev/null
+++ b/test/simulation/108-peer
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+. test.common
+
+test_start "NTP peers"
+
+# Allow and drop packets to the server in 1000 second intervals, so only one
+# client has access to it and the other is forced to switch to the peer.
+base_delay=$(cat <<-EOF | tr -d '\n'
+  (+ 1e-4
+     (* -1
+        (equal 0.1 from 2)
+        (equal 0.1 to 1)
+        (equal 0.1 (min (% time 2000) 1000) 1000))
+     (* -1
+        (equal 0.1 from 3)
+        (equal 0.1 to 1)
+	(equal 0.1 (max (% time 2000) 1000) 1000)))
+EOF
+)
+
+clients=2
+peers=2
+max_sync_time=1000
+client_server_options="minpoll 6 maxpoll 6"
+client_peer_options="minpoll 6 maxpoll 6"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+check_source_selection || test_fail
+check_sync || test_fail
+
+test_pass
diff --git a/test/simulation/109-makestep b/test/simulation/109-makestep
new file mode 100755
index 0000000..e74b719
--- /dev/null
+++ b/test/simulation/109-makestep
@@ -0,0 +1,30 @@
+#!/bin/bash
+
+. test.common
+test_start "makestep directive"
+
+limit=200
+jitter=1e-5
+client_conf="makestep 2 1"
+
+min_sync_time=140
+max_sync_time=160
+
+for time_offset in -1.0 -0.1 0.1 1.0; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+done
+
+min_sync_time=120
+max_sync_time=140
+
+for time_offset in -1e8 -1e2 1e2 1e8; do
+	run_test || test_fail
+	check_chronyd_exit || test_fail
+	check_source_selection || test_fail
+	check_sync || test_fail
+done
+
+test_pass
diff --git a/test/simulation/110-chronyc b/test/simulation/110-chronyc
new file mode 100755
index 0000000..535a126
--- /dev/null
+++ b/test/simulation/110-chronyc
@@ -0,0 +1,37 @@
+#!/bin/bash
+
+. test.common
+
+test_start "chronyc"
+
+chronyc_conf="tracking
+sources
+sourcestats"
+
+run_test || test_fail
+check_chronyd_exit || test_fail
+
+check_chronyc_output "^Reference ID    : 192\.168\.123\.1 \(192\.168\.123\.1\)
+Stratum         : 2
+Ref time \(UTC\)  : Fri Jan  1 00:1.:.. 2010
+System time     : 0\.0000..... seconds (slow|fast) of NTP time
+Last offset     : -?0\.0000..... seconds
+RMS offset      : 0\.000...... seconds
+Frequency       : (99|100)\.... ppm fast
+Residual freq   : -?0.00. ppm
+Skew            : 0\.... ppm
+Root delay      : 0\.000... seconds
+Root dispersion : 0.000... seconds
+Update interval : 6.\.. seconds
+Leap status     : Normal
+210 Number of sources = 1
+MS Name/IP address         Stratum Poll Reach LastRx Last sample
+===============================================================================
+\^\* 192\.168\.123\.1                 1   [67]   377    [0-9]+ [0-9 +-]+[un]s\[[0-9 +-]+[un]s\] \+/-[ 0-9]+[un]s
+210 Number of sources = 1
+Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
+==============================================================================
+192\.168\.123\.1              [0-9 ]+ [0-9 ]+ [0-9 ]+ [ +-]0\.0..      0\....  [0-9 +-]+[un]s [0-9 ]+[un]s$" \
+|| test_fail
+
+test_pass
diff --git a/test/simulation/201-freqaccumulation b/test/simulation/201-freqaccumulation
new file mode 100755
index 0000000..a8ba917
--- /dev/null
+++ b/test/simulation/201-freqaccumulation
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+. test.common
+
+# Test fix in commit 60d0fa299307076143da94d36deb7b908fa9bdb7
+
+test_start "frequency accumulation"
+
+time_offset=100.0
+jitter=1e-6
+base_delay=1e-6
+wander=0.0
+
+limit=200
+time_max_limit=1e-5
+freq_max_limit=1e-7
+time_rms_limit=1e-5
+freq_rms_limit=1e-7
+min_sync_time=120
+max_sync_time=140
+
+client_server_options="minpoll 6 maxpoll 6"
+client_conf="driftfile tmp/drift
+makestep 1 1"
+
+for freq_offset in -5e-2 -5e-4 5e-4 5e-2; do
+	for drift in -1e+4 -1e+2 1e+2 1e+4; do
+		echo "$drift 100000" > tmp/drift
+		run_test || test_fail
+		check_chronyd_exit || test_fail
+		check_sync || test_fail
+	done
+done
+
+test_pass
diff --git a/test/simulation/README b/test/simulation/README
new file mode 100644
index 0000000..c875ad6
--- /dev/null
+++ b/test/simulation/README
@@ -0,0 +1,12 @@
+This is a collection of simulation tests. They use clknetsim to simulate
+multiple systems connected in a network. It's available at
+
+https://github.com/mlichvar/clknetsim
+
+If this directory doesn't have a clknetsim subdirectory, a known working
+revision will be downloaded and compiled automatically.
+
+Currently it runs only on Linux.
+
+The tests are written in bash and they can be run directly. The ./run script
+runs all tests.
diff --git a/test/simulation/test.common b/test/simulation/test.common
new file mode 100644
index 0000000..6635128
--- /dev/null
+++ b/test/simulation/test.common
@@ -0,0 +1,413 @@
+# Copyright (C) 2013-2014  Miroslav Lichvar <mlichvar@redhat.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
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+export LC_ALL=C
+export PATH=../../:$PATH
+export CLKNETSIM_PATH=clknetsim
+
+# Known working clknetsim revision
+clknetsim_revision=eb0b85335c40027ac941b2276142542fff482107
+clknetsim_url=https://github.com/mlichvar/clknetsim/archive/$clknetsim_revision.tar.gz
+
+# Only Linux is supported
+if [ "$(uname -s)" != Linux ]; then
+	echo "Simulation tests supported only on Linux"
+	exit 3
+fi
+
+# Try to download clknetsim if not found
+if [ ! -e $CLKNETSIM_PATH ]; then
+	curl -L "$clknetsim_url" | tar xz || exit 3
+	ln -s clknetsim-$clknetsim_revision clknetsim || exit 3
+fi
+
+# Try to build clknetsim if not built
+if [ ! -x $CLKNETSIM_PATH/clknetsim -o ! -e $CLKNETSIM_PATH/clknetsim.so ]; then
+	make -C clknetsim || exit 3
+fi
+
+. $CLKNETSIM_PATH/clknetsim.bash
+
+# Default test testings
+
+default_limit=10000
+default_time_offset=1e-1
+default_freq_offset=1e-4
+default_base_delay=1e-4
+default_jitter=1e-4
+default_wander=1e-9
+default_refclock_jitter=""
+
+default_update_interval=0
+default_log_packets=0
+default_shift_pll=2
+
+default_server_strata=1
+default_servers=1
+default_clients=1
+default_peers=0
+default_server_start=0.0
+default_client_start=0.0
+default_chronyc_start=1000.0
+default_server_step=""
+default_client_step=""
+
+default_server_server_options=""
+default_client_server_options=""
+default_server_peer_options=""
+default_client_peer_options=""
+default_server_conf=""
+default_client_conf=""
+default_chronyc_conf=""
+default_chronyd_options=""
+
+default_time_max_limit=1e-3
+default_freq_max_limit=5e-4
+default_time_rms_limit=2e-4
+default_freq_rms_limit=1e-5
+default_min_sync_time=120
+default_max_sync_time=210
+
+# Initialize test settings from their defaults
+for defopt in $(declare | grep '^default_'); do
+	defoptname=${defopt%%=*}
+	optname=${defoptname#default_}
+	eval "[ -z \"\${$optname:+a}\" ] && $optname=\"\$$defoptname\""
+done
+
+test_start() {
+	rm -f tmp/*
+	echo "Testing $@:"
+}
+
+test_pass() {
+	echo "PASS"
+	exit 0
+}
+
+test_fail() {
+	echo "FAIL"
+	exit 1
+}
+
+test_ok() {
+	pad_line
+	echo -e "\tOK"
+	return 0
+}
+
+test_bad() {
+	pad_line
+	echo -e "\tBAD"
+	return 1
+}
+
+test_error() {
+	pad_line
+	echo -e "\tERROR"
+	return 1
+}
+
+msg_length=0
+pad_line() {
+	local line_length=56
+	[ $msg_length -lt $line_length ] && \
+		printf "%$[$line_length - $msg_length]s" ""
+	msg_length=0
+}
+
+# Print aligned message
+test_message() {
+	local level=$1 eol=$2
+	shift 2
+	local msg="$*"
+
+	while [ $level -gt 0 ]; do
+		echo -n "  "
+		level=$[$level - 1]
+		msg_length=$[$msg_length + 2]
+	done
+	echo -n "$msg"
+
+	msg_length=$[$msg_length + ${#msg}]
+	if [ $eol -ne 0 ]; then
+		echo
+		msg_length=0
+	fi
+}
+
+get_wander_expr() {
+	local scaled_wander
+
+	scaled_wander=$(awk "BEGIN {print $wander / \
+		sqrt($update_interval < 0 ? 2^-($update_interval) : 1)}")
+
+	echo "(+ $freq_offset (sum (* $scaled_wander (normal))))"
+}
+
+
+get_delay_expr() {
+	echo "(+ $base_delay (* $jitter (exponential)))"
+}
+
+get_refclock_expr() {
+	echo "(* $refclock_jitter (normal))"
+}
+
+get_chronyd_nodes() {
+	echo $[$servers * $server_strata + $clients]
+}
+
+get_chronyd_conf() {
+	local i stratum=$1 peer=$2
+
+	if [ $stratum -eq 1 ]; then
+		echo "local stratum 1"
+		echo "$server_conf"
+	elif [ $stratum -le $server_strata ]; then
+		for i in $(seq 1 $servers); do
+			echo "server 192.168.123.$[$servers * ($stratum - 2) + $i] $server_server_options"
+		done
+		for i in $(seq 1 $peers); do
+			[ $i -eq $peer -o $i -gt $servers ] && continue
+			echo "peer 192.168.123.$[$servers * ($stratum - 1) + $i] $server_peer_options"
+		done
+		echo "$server_conf"
+	else
+		for i in $(seq 1 $servers); do
+			echo "server 192.168.123.$[$servers * ($stratum - 2) + $i] $client_server_options"
+		done
+		for i in $(seq 1 $peers); do
+			[ $i -eq $peer -o $i -gt $clients ] && continue
+			echo "peer 192.168.123.$[$servers * ($stratum - 1) + $i] $client_peer_options"
+		done
+		echo "$client_conf"
+	fi
+}
+
+# Check if the clock was well synchronized
+check_sync() {
+	local i sync_time max_time_error max_freq_error ret=0
+	local rms_time_error rms_freq_error
+
+	test_message 2 1 "checking clock sync time, max/rms time/freq error:"
+
+	for i in $(seq 1 $(get_chronyd_nodes)); do
+		[ $i -gt $[$servers * $server_strata] ] || continue
+
+		sync_time=$(find_sync tmp/log.offset tmp/log.freq $i \
+			$time_max_limit $freq_max_limit 1.0)
+		max_time_error=$(get_stat 'Maximum absolute offset' $i)
+		max_freq_error=$(get_stat 'Maximum absolute frequency' $i)
+		rms_time_error=$(get_stat 'RMS offset' $i)
+		rms_freq_error=$(get_stat 'RMS frequency' $i)
+
+		test_message 3 0 "node $i: $sync_time $(printf '%.2e %.2e %.2e %.2e' \
+			$max_time_error $max_freq_error $rms_time_error $rms_freq_error)"
+
+		check_stat $sync_time $min_sync_time $max_sync_time && \
+			check_stat $max_time_error 0.0 $time_max_limit && \
+			check_stat $max_freq_error 0.0 $freq_max_limit && \
+			check_stat $rms_time_error 0.0 $time_rms_limit && \
+			check_stat $rms_freq_error 0.0 $freq_rms_limit && \
+			test_ok || test_bad
+
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check if chronyd exited properly
+check_chronyd_exit() {
+	local i ret=0
+
+	test_message 2 1 "checking chronyd exit:"
+
+	for i in $(seq 1 $(get_chronyd_nodes)); do
+		test_message 3 0 "node $i:"
+
+		tail -n 1 tmp/log.$i | grep -q 'chronyd exiting' && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check for problems in source selection
+check_source_selection() {
+	local i ret=0
+
+	test_message 2 1 "checking source selection:"
+
+	for i in $(seq $[$servers * $server_strata + 1] $(get_chronyd_nodes)); do
+		test_message 3 0 "node $i:"
+
+		! grep -q 'no majority\|no reachable sources' tmp/log.$i && \
+			grep -q 'Selected source' tmp/log.$i && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Check if incoming and outgoing packet intervals are sane
+check_packet_interval() {
+	local i ret=0 in_interval out_interval
+
+	test_message 2 1 "checking incoming and outgoing packet interval:"
+
+	for i in $(seq 1 $(get_chronyd_nodes)); do
+		in_interval=$(get_stat 'Mean incoming packet interval' $i)
+		out_interval=$(get_stat 'Mean outgoing packet interval' $i)
+
+		test_message 3 0 "node $i: $(printf '%.2e %.2e' \
+			$in_interval $out_interval)"
+
+		# Check that the intervals are non-zero and shorter than limit,
+		# incoming is not longer than outgoing for stratum 1 servers, and
+		# outgoing is not longer than incoming for clients.
+		nodes=$[$servers * $server_strata + $clients]
+		check_stat $in_interval 0.1 $limit && \
+			check_stat $out_interval 0.1 $limit && \
+			([ $i -gt $servers ] || \
+				check_stat $in_interval 0.0 $out_interval) && \
+			([ $i -le $[$servers * $server_strata] ] || \
+				check_stat $in_interval 0.0 $out_interval) && \
+			test_ok || test_bad
+
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Compare chronyc output with specified pattern
+check_chronyc_output() {
+	local i ret=0 pattern=$1
+
+	test_message 2 1 "checking chronyc output:"
+
+	for i in $(seq $[$(get_chronyd_nodes) + 1] $[$(get_chronyd_nodes) + $clients]); do
+		test_message 3 0 "node $i:"
+
+		[[ "$(cat tmp/log.$i)" =~ $pattern ]] && \
+			test_ok || test_bad
+		[ $? -eq 0 ] || ret=1
+	done
+
+	return $ret
+}
+
+# Print test settings which differ from default value
+print_nondefaults() {
+	local defopt defoptname optname
+
+	test_message 2 1 "non-default settings:"
+	declare | grep '^default_*' | while read defopt; do
+		defoptname=${defopt%%=*}
+		optname=${defoptname#default_}
+		eval "[ \"\$$optname\" = \"\$$defoptname\" ]" || \
+			test_message 3 1 $(eval "echo $optname=\$$optname")
+	done
+}
+
+run_simulation() {
+	local nodes=$1
+
+	test_message 2 0 "running simulation:"
+
+	start_server $nodes \
+		-o tmp/log.offset -f tmp/log.freq \
+		$([ $log_packets -ne 0 ] && echo -p tmp/log.packets) \
+		-R $(awk "BEGIN {print $update_interval < 0 ? 2^-($update_interval) : 1}") \
+		-r $(awk "BEGIN {print $max_sync_time * 2^$update_interval}") \
+		-l $(awk "BEGIN {print $limit * 2^$update_interval}") && test_ok || test_error
+}
+
+run_test() {
+	local i j n stratum node nodes step start freq offset conf
+
+	test_message 1 1 "network with $servers*$server_strata servers and $clients clients:"
+	print_nondefaults
+
+	nodes=$(get_chronyd_nodes)
+	[ -n "$chronyc_conf" ] && nodes=$[$nodes + $clients]
+
+	for i in $(seq 1 $nodes); do
+		echo "node${i}_shift_pll = $shift_pll"
+		for j in $(seq 1 $nodes); do
+			[ $i -eq $j ] && continue
+			echo "node${i}_delay${j} = $(get_delay_expr)"
+			echo "node${j}_delay${i} = $(get_delay_expr)"
+		done
+	done > tmp/conf
+
+	node=1
+
+	for stratum in $(seq 1 $[$server_strata + 1]); do
+		[ $stratum -le $server_strata ] && n=$servers || n=$clients
+
+		for i in $(seq 1 $n); do
+			test_message 2 0 "starting node $node:"
+			if [ $stratum -eq 1 ]; then
+				step=$server_step
+				start=$server_start
+				freq=""
+				offset=0.0
+			elif [ $stratum -le $server_strata ]; then
+				step=$server_step
+				start=$server_start
+				freq=$(get_wander_expr)
+				offset=0.0
+			else
+				step=$client_step
+				start=$client_start
+				freq=$(get_wander_expr)
+				offset=$time_offset
+			fi
+
+			conf=$(get_chronyd_conf $stratum $i $n)
+
+			[ -z "$freq" ] || echo "node${node}_freq = $freq" >> tmp/conf
+			[ -z "$step" ] || echo "node${node}_step = $step" >> tmp/conf
+			[ -z "$refclock_jitter" ] || \
+				echo "node${node}_refclock = $(get_refclock_expr)" >> tmp/conf
+			echo "node${node}_offset = $offset" >> tmp/conf
+			echo "node${node}_start = $start" >> tmp/conf
+			start_client $node chronyd "$conf" "" "$chronyd_options" && \
+				test_ok || test_error
+
+			[ $? -ne 0 ] && return 1
+			node=$[$node + 1]
+		done
+	done
+
+	for i in $(seq 1 $[$nodes - $node + 1]); do
+		test_message 2 0 "starting node $node:"
+
+		echo "node${node}_start = $chronyc_start" >> tmp/conf
+		start_client $node chronyc "$chronyc_conf" "" \
+			"-n -h 192.168.123.$[$node - $clients]" && \
+			test_ok || test_error
+
+		[ $? -ne 0 ] && return 1
+		node=$[$node + 1]
+	done
+
+	run_simulation $nodes
+}