diff --git a/ovl/ovs/README.md b/ovl/ovs/README.md
new file mode 100644
index 00000000..c3c376a5
--- /dev/null
+++ b/ovl/ovs/README.md
@@ -0,0 +1,78 @@
+# Xcluster/ovl - ovs
+
+Open vSwitch is used in the xcluster VMs, not on the host as a VM-VM
+network (as the image on https://www.openvswitch.org/ shows).
+
+
+## Usage
+
+Test;
+```
+./ovs.sh test > $log
+```
+
+Manual tests;
+```
+./ovs.sh test start_base > $log
+# On a VM;
+ovs-vsctl -V
+grep -v JSON /etc/openvswitch/conf.db | jq
+ovs-vsctl add-br br0
+ovs-appctl dpctl/show
+#ovs-vsctl add-br br1 -- set Bridge br1 datapath_type=netdev
+ovs-appctl dpif/show-dp-features br0
+ovs-vsctl add-port br0 eth1
+ovs-vsctl add-port br0 vlan10 tag=10 -- set Interface vlan10 type=internal
+i=$(hostname | cut -d- -f2 | sed -re 's,^0+,,')
+ip link set up dev vlan10
+ip addr add 3000::$i/120 dev vlan10
+ping -c1 3000::$i
+```
+
+
+## Build
+
+```
+# Clone;
+mkdir -p $GOPATH/src/github.com/openvswitch
+cd $GOPATH/src/github.com/openvswitch
+git clone --depth=1 https://github.com/openvswitch/ovs.git
+# Build;
+cdo ovs
+eval $(./ovs.sh env | grep SYSD)
+cd $GOPATH/src/github.com/openvswitch/ovs
+./boot.sh
+./configure
+make -j$(nproc)
+make DESTDIR=$SYSD install
+```
+
+### Build with XDP support
+
+[afxdp doc](https://docs.openvswitch.org/en/latest/intro/install/afxdp/)
+
+```
+cdo xdp
+./xdp.sh libbpf_build
+cdo ovs
+eval $(./ovs.sh env | grep SYSD)
+eval $(xc env | grep -e '__kobj')
+bpflibd=$(readlink -f $__kobj/source)/tools/lib/bpf/build/usr
+cd $GOPATH/src/github.com/openvswitch/ovs
+LDFLAGS=-L$bpflibd/lib64 CPPFLAGS=-I$bpflibd/include ./configure --enable-afxdp
+make -j$(nproc)
+make DESTDIR=$SYSD install
+```
+
+## Links
+
+In no particular order or usefulness.
+
+* https://www.openvswitch.org/
+* https://github.com/openvswitch/ovs/
+* https://kumul.us/switches-ovs-vs-linux-bridge-simplicity-rules/
+* https://www.plixer.com/blog/openflow-vs-netflow/
+* https://www.linuxtechi.com/install-use-openvswitch-kvm-centos-7-rhel-7/
+* https://arthurchiao.art/blog/ovs-deep-dive-6-internal-port/
+* https://arthurchiao.art/blog/ovs-deep-dive-1-vswitchd/
+
diff --git a/ovl/ovs/default/bin/ovs_test b/ovl/ovs/default/bin/ovs_test
new file mode 100755
index 00000000..6445dd7d
--- /dev/null
+++ b/ovl/ovs/default/bin/ovs_test
@@ -0,0 +1,115 @@
+#! /bin/sh
+##
+## ovs_test --
+##
+##   Test script for ovs executed in xcluster.
+##
+## Commands;
+##
+
+prg=$(basename $0)
+dir=$(dirname $0); dir=$(readlink -f $dir)
+me=$dir/$prg
+tmp=/tmp/${prg}_$$
+test -n "$DOMAIN" || DOMAIN=xcluster
+
+die() {
+	echo "ERROR: $*" >&2
+	rm -rf $tmp
+	exit 1
+}
+help() {
+	grep '^##' $0 | cut -c3-
+	rm -rf $tmp
+	exit 0
+}
+test -n "$1" || help
+echo "$1" | grep -qi "^help\|-h" && help
+
+log() {
+	echo "$prg: $*" >&2
+}
+dbg() {
+	test -n "$__verbose" && echo "$prg: $*" >&2
+}
+
+cmd_tcase_create_br0() {
+	tcase "Create ovs bridge; br0"
+	ovs-vsctl add-br br0
+	ovs-vsctl add-port br0 eth1
+}
+cmd_tcase_create_netns() {
+	tcase "Create netns; ns1, ns2"
+	create_netns ns1
+	create_netns ns2
+}
+create_netns() {
+	ip netns add $1
+	ip netns exec $1 ip link set up dev lo
+}
+cmd_tcase_add_ports() {
+	tcase "Add vanilla interfaces in netns's"
+	ovs-vsctl add-port br0 ns1 -- set Interface ns1 type=internal
+	ovs-vsctl add-port br0 ns2 -- set Interface ns2 type=internal
+	add_ports 1
+	add_ports 2
+}
+add_ports() {
+	local i=$(hostname | cut -d- -f2 | sed -re 's,^0+,,')
+	local ns=ns$1
+	local ip4=10.10.$i.$1
+	ip link set netns $ns $ns
+	ip netns exec $ns ip link set up dev $ns
+	ip netns exec $ns ip addr add $ip4/16 dev $ns
+	ip netns exec $ns ip -6 addr add 1100::$ip4/112 dev $ns
+}
+cmd_tcase_ping_all() {
+	tcase "Ping all from ns1 and ns2"
+	ping_all 1
+	ping_all 2
+}
+ping_all() {
+	local ns=ns$1
+	local i
+	for i in $(seq 1 $__nvm); do
+		ping_one $ns 10.10.$i.1 || tdie 10.10.$i.1
+		ping_one $ns 10.10.$i.2 || tdie 10.10.$i.2
+		tex ping_one $ns 1100::10.10.$i.1 || tdie 1100::10.10.$i.1
+		tex ping_one $ns 1100::10.10.$i.2 || tdie 1100::10.10.$i.2
+	done
+}
+ping_one() {
+	ip netns exec $1 ping -W1 -c1 $2
+}
+
+
+. /etc/profile
+. /usr/lib/xctest
+indent='  '
+
+
+# Get the command
+cmd=$1
+shift
+grep -q "^cmd_$cmd()" $0 || die "Invalid command [$cmd]"
+
+while echo "$1" | grep -q '^--'; do
+	if echo $1 | grep -q =; then
+		o=$(echo "$1" | cut -d= -f1 | sed -e 's,-,_,g')
+		v=$(echo "$1" | cut -d= -f2-)
+		eval "$o=\"$v\""
+	else
+		o=$(echo "$1" | sed -e 's,-,_,g')
+		eval "$o=yes"
+	fi
+	shift
+done
+unset o v
+long_opts=`set | grep '^__' | cut -d= -f1`
+
+# Execute command
+trap "die Interrupted" INT TERM
+cmd_$cmd "$@"
+status=$?
+rm -rf $tmp
+exit $status
diff --git a/ovl/ovs/default/etc/init.d/20ovs.rc b/ovl/ovs/default/etc/init.d/20ovs.rc
new file mode 100755
index 00000000..925c1a57
--- /dev/null
+++ b/ovl/ovs/default/etc/init.d/20ovs.rc
@@ -0,0 +1,21 @@
+#! /bin/sh
+
+export PATH="/bin:/sbin:/usr/bin:/usr/sbin"
+. /etc/profile
+
+die() {
+	echo "$@"
+	exit 1
+}
+
+hostname | grep -Eq 'vm-[0-9]+$' || die "Invalid hostname [$(hostname)]"
+i=$(hostname | cut -d- -f2 | sed -re 's,^0+,,')
+test $i -gt 200 && exit 0
+
+SYSTEM_ID=$(printf '35f15062-7e2b-11e9-b640-0000000100%02x\n' $i)
+echo $SYSTEM_ID > /etc/machine-id
+mkdir -p /etc/openvswitch
+echo $SYSTEM_ID > /etc/openvswitch/system-id.conf
+ovsdb-tool create /etc/openvswitch/conf.db /usr/local/share/openvswitch/vswitch.ovsschema
+
+/usr/local/share/openvswitch/scripts/ovs-ctl --system-id=$SYSTEM_ID start
diff --git a/ovl/ovs/ovs.sh b/ovl/ovs/ovs.sh
new file mode 100755
index 00000000..c51482a2
--- /dev/null
+++ b/ovl/ovs/ovs.sh
@@ -0,0 +1,142 @@
+#! /bin/sh
+##
+## ovs.sh --
+##
+##   Help script for xcluster ovl/ovs.
+##
+## Commands;
+##
+
+prg=$(basename $0)
+dir=$(dirname $0); dir=$(readlink -f $dir)
+me=$dir/$prg
+tmp=/tmp/${prg}_$$
+
+die() {
+    echo "ERROR: $*" >&2
+    rm -rf $tmp
+    exit 1
+}
+help() {
+    grep '^##' $0 | cut -c3-
+    rm -rf $tmp
+    exit 0
+}
+test -n "$1" || help
+echo "$1" | grep -qi "^help\|-h" && help
+
+log() {
+	echo "$prg: $*" >&2
+}
+dbg() {
+	test -n "$__verbose" && echo "$prg: $*" >&2
+}
+
+##   env
+##     Print environment.
+##
+cmd_env() {
+
+	test -n "$SYSD" || SYSD=$XCLUSTER_WORKSPACE/sys
+	if test "$cmd" = "env"; then
+		set | grep -E '^(__.*|SYSD)='
+		return 0
+	fi
+
+	test -n "$XCLUSTER" || die 'Not set [$XCLUSTER]'
+	test -x "$XCLUSTER" || die "Not executable [$XCLUSTER]"
+	eval $($XCLUSTER env)
+}
+
+##   test --list
+##   test [--xterm] [test...] > logfile
+##     Exec tests
+##
+cmd_test() {
+	if test "$__list" = "yes"; then
+        grep '^test_' $me | cut -d'(' -f1 | sed -e 's,test_,,'
+        return 0
+    fi
+
+	cmd_env
+    start=starts
+    test "$__xterm" = "yes" && start=start
+    rm -f $XCLUSTER_TMP/cdrom.iso
+
+    if test -n "$1"; then
+        for t in $@; do
+            test_$t
+        done
+    else
+		test_default
+    fi      
+
+    now=$(date +%s)
+    tlog "Xcluster test ended. Total time $((now-begin)) sec"
+
+}
+
+test_start_base() {
+	export __image=$XCLUSTER_HOME/hd.img
+	echo "$XOVLS" | grep -q private-reg && unset XOVLS
+	export __nrouters=0
+	test -n "$TOPOLOGY" && \
+		. $($XCLUSTER ovld network-topology)/$TOPOLOGY/Envsettings
+	xcluster_start network-topology iptools ovs
+}
+
+test_default() {
+	tlog "=== ovs: Basic test"
+	test_start_base
+	otcw create_br0
+	otcw create_netns
+	otcw add_ports
+	otcw ping_all
+	xcluster_stop
+}
+
+##   man [command]
+##     Show a ovs man-page. List if no command is specified.
+cmd_man() {
+	cmd_env
+	MANPATH=$SYSD/usr/local/share/man
+	if test -z "$1"; then
+		local f
+		for f in $(find $MANPATH -type f); do
+			basename $f
+		done
+		return 0
+	fi
+	export MANPATH
+	xterm -bg '#ddd' -fg '#222' -geometry 80x45 -T $1 -e man $1 &
+}
+
+##
+. $($XCLUSTER ovld test)/default/usr/lib/xctest
+indent=''
+
+# Get the command
+cmd=$1
+shift
+grep -q "^cmd_$cmd()" $0 $hook || die "Invalid command [$cmd]"
+
+while echo "$1" | grep -q '^--'; do
+    if echo $1 | grep -q =; then
+	o=$(echo "$1" | cut -d= -f1 | sed -e 's,-,_,g')
+	v=$(echo "$1" | cut -d= -f2-)
+	eval "$o=\"$v\""
+    else
+	o=$(echo "$1" | sed -e 's,-,_,g')
+	eval "$o=yes"
+    fi
+    shift
+done
+unset o v
+long_opts=`set | grep '^__' | cut -d= -f1`
+
+# Execute command
+trap "die Interrupted" INT TERM
+cmd_$cmd "$@"
+status=$?
+rm -rf $tmp
+exit $status
diff --git a/ovl/ovs/tar b/ovl/ovs/tar
new file mode 100755
index 00000000..404d47cd
--- /dev/null
+++ b/ovl/ovs/tar
@@ -0,0 +1,45 @@
+#! /bin/sh
+# NOTE: A common pattern is to specify "-" (stdout) as out-file,
+#  so there must be NO log printouts to stdout!
+
+dir=$(dirname $0); dir=$(readlink -f $dir)
+tmp=/tmp/$USER/xcluster_$$
+die() {
+	echo "ERROR: $*" >&2
+	rm -rf $tmp
+	exit 1
+}
+log() {
+	echo "INFO: $*" >&2
+}
+
+test -n "$1" || die "No out-file"
+
+mkdir -p $tmp
+cp -R $dir/default/* $tmp
+
+eval $($dir/ovs.sh env | grep SYSD)
+OVSD=$SYSD/usr/local
+test -x $OVSD/bin/ovs-vsctl || die "Ovs not built?"
+$XCLUSTER install_prog --dest=$tmp $OVSD/sbin/ovs*
+$XCLUSTER install_prog --dest=$tmp $OVSD/bin/ovs*
+mkdir -p $tmp/usr/local/share
+cp -R $OVSD/share/openvswitch $tmp/usr/local/share
+rm -r $tmp/usr/local/share/openvswitch/python
+eval $($XCLUSTER env | grep __kobj)
+bpflibd=$(readlink -f $__kobj/source)/tools/lib/bpf/build/usr
+f=$bpflibd/lib64/libbpf.so.0
+if test -r $f; then
+	log "Including libbpf.so"
+	mkdir -p $tmp/usr/lib/x86_64-linux-gnu
+	cp -L $f $tmp/usr/lib/x86_64-linux-gnu
+else
+	log "NOT including libbpf.so"
+fi
+
+$XCLUSTER install_prog --dest=$tmp jq
+
+cd $tmp
+tar cf "$1" *
+cd - > /dev/null
+rm -rf $tmp