diff --git a/Documentation/automake.mk b/Documentation/automake.mk
index 5968d6941..bf2166349 100644
--- a/Documentation/automake.mk
+++ b/Documentation/automake.mk
@@ -106,7 +106,7 @@ RST_MANPAGES = \
 # rST formatted manpages that we don't want to install because they
 # document stuff that only works with a build tree, not with an
 # installed OVS.
-RST_MANPAGES_NOINST = ovs-sim.1.rst
+RST_MANPAGES_NOINST = ovn-sim.1.rst
 
 # The GNU standards say that these variables should control
 # installation directories for manpages in each section.  Automake
diff --git a/Documentation/conf.py b/Documentation/conf.py
index 6bf528bde..2c85dcf4d 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -114,8 +114,8 @@ html_static_path = ['_static']
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
 _man_pages = [
-    ('ovs-sim.1',
-     u'Open vSwitch simulator environment'),
+    ('ovn-sim.1',
+     u'Open Virtual Network simulator environment'),
     ('ovsdb-server.7',
      u'Open vSwitch Database Server Protocol'),
     ('ovsdb.5',
diff --git a/Documentation/ref/index.rst b/Documentation/ref/index.rst
index 530d639d6..7ff9edd09 100644
--- a/Documentation/ref/index.rst
+++ b/Documentation/ref/index.rst
@@ -39,7 +39,7 @@ time:
 .. toctree::
    :maxdepth: 3
 
-   ovs-sim.1
+   ovn-sim.1
    ovsdb-server.7
    ovsdb.5
    ovsdb.7
diff --git a/Documentation/ref/ovn-sim.1.rst b/Documentation/ref/ovn-sim.1.rst
new file mode 100644
index 000000000..b906740f0
--- /dev/null
+++ b/Documentation/ref/ovn-sim.1.rst
@@ -0,0 +1,122 @@
+=======
+ovn-sim
+=======
+
+Synopsis
+========
+
+``ovn-sim`` [*option*]... [*script*]...
+
+Description
+===========
+
+``ovn-sim`` is a wrapper script that adds ovn related commands on
+top of ``ovs-sim``.
+
+``ovs-sim`` provides a convenient environment for running one or more Open
+vSwitch instances and related software in a sandboxed simulation environment.
+
+To use ``ovn-sim``, first build Open vSwitch, then invoke it directly from the
+build directory, e.g.::
+
+    git clone https://github.com/openvswitch/ovs.git
+    cd ovs
+    ./boot.sh && ./configure && make
+    cd ..
+    git clone https://github.com/ovn-org/ovn.git
+    cd ovn
+    ./boot.sh && ./configure --with-ovs-source=${PWD}/../ovs
+    make
+    utilities/ovn-sim
+
+See documentation on ``ovs-sim`` for info on simulator, including the
+parameters you can use.
+
+OVN Commands
+------------
+
+These commands interact with OVN, the Open Virtual Network.
+
+``ovn_start`` [*options*]
+    Creates and initializes the central OVN databases (both
+    ``ovn-sb(5)`` and ``ovn-nb(5)``) and starts an instance of
+    ``ovsdb-server`` for each one.  Also starts an instance of
+    ``ovn-northd``.
+
+    The following options are available:
+
+       ``--nbdb-model`` *model*
+           Uses the given database model for the northbound database.
+           The *model* may be ``standalone`` (the default), ``backup``,
+           or ``clustered``.
+
+       ``--nbdb-servers`` *n*
+           For a clustered northbound database, the number of servers in
+           the cluster.  The default is 3.
+
+       ``--sbdb-model`` *model*
+           Uses the given database model for the southbound database.
+           The *model* may be ``standalone`` (the default), ``backup``,
+           or ``clustered``.
+
+       ``--sbdb-servers`` *n*
+           For a clustered southbound database, the number of servers in
+           the cluster.  The default is 3.
+
+``ovn_attach`` *network* *bridge* *ip* [*masklen*]
+    First, this command attaches bridge to interconnection network
+    network, just like ``net_attach`` *network* *bridge*.  Second, it
+    configures (simulated) IP address *ip* (with network mask length
+    *masklen*, which defaults to 24) on *bridge*. Finally, it
+    configures the Open vSwitch database to work with OVN and starts
+    ``ovn-controller``.
+
+Examples
+========
+
+Simulating hypervisors and and starting ovn controller (via ovn_attach) on each::
+
+    ovn_start
+    ovn-nbctl ls-add lsw0
+    net_add n1
+    for i in 0 1; do
+        sim_add hv$i
+        as hv$i
+        ovs-vsctl add-br br-phys
+        ovn_attach n1 br-phys 192.168.0.`expr $i + 1`
+        ovs-vsctl add-port br-int vif$i -- set Interface vif$i external-ids:iface-id=lp$i
+        ovn-nbctl lsp-add lsw0 lp$i
+        ovn-nbctl lsp-set-addresses lp$i f0:00:00:00:00:0$i
+    done
+
+Here’s a primitive OVN "scale test" (adjust the scale by changing
+``n`` in the first line)::
+
+    n=200; export n
+    ovn_start --sbdb-model=clustered
+    net_add n1
+    ovn-nbctl ls-add br0
+    for i in `seq $n`; do
+        (sim_add hv$i
+        as hv$i
+        ovs-vsctl add-br br-phys
+        y=$(expr $i / 256)
+        x=$(expr $i % 256)
+        ovn_attach n1 br-phys 192.168.$y.$x
+        ovs-vsctl add-port br-int vif$i -- set Interface vif$i external-ids:iface-id=lp$i) &
+        case $i in
+            *50|*00) echo $i; wait ;;
+        esac
+    done
+    wait
+    for i in `seq $n`; do
+        yy=$(printf %02x $(expr $i / 256))
+        xx=$(printf %02x $(expr $i % 256))
+        ovn-nbctl lsp-add br0 lp$i
+        ovn-nbctl lsp-set-addresses lp$i f0:00:00:00:$yy:$xx
+    done
+
+When the scale test has finished initializing, you can watch the
+logical ports come up with a command like this::
+
+    watch 'for i in `seq $n`; do if test `ovn-nbctl lsp-get-up lp$i` != up; then echo $i; fi; done'
diff --git a/Documentation/ref/ovs-sim.1.rst b/Documentation/ref/ovs-sim.1.rst
deleted file mode 100644
index 4382598e1..000000000
--- a/Documentation/ref/ovs-sim.1.rst
+++ /dev/null
@@ -1,244 +0,0 @@
-=======
-ovs-sim
-=======
-
-Synopsis
-========
-
-``ovs-sim`` [*option*]... [*script*]...
-
-Description
-===========
-
-``ovs-sim`` provides a convenient environment for running one or more Open
-vSwitch instances and related software in a sandboxed simulation environment.
-
-To use ``ovs-sim``, first build Open vSwitch, then invoke it directly from the
-build directory, e.g.::
-
-    git clone https://github.com/openvswitch/ovs.git
-    cd ovs
-    ./configure
-    make
-    utilities/ovs-sim
-
-When invoked in the most ordinary way as shown above, ovs-sim does  the
-following:
-
-1. Creates a directory ``sandbox`` as a subdirectory of the current
-   directory (first destroying such a directory if it already exists)
-   and makes it the current directory.
-
-2. Installs all of the Open vSwitch manpages into a ``man``
-   subdirectory of sandbox and adjusts the ``MANPATH`` environment
-   variable so that ``man`` and other manpage viewers can find them.
-
-3. Creates a simulated Open vSwitch named ``main`` and sets it up as the
-   default target for OVS commands, as if the following ``ovs-sim``
-   commands had been run::
-
-            sim_add main
-            as main
-
-  See `Commands`_, below, for an explanation.
-
-4. Runs  any  scripts  specified on the command line (see `Options`_,
-   below). The scripts can use arbitrary Bash  syntax,  plus  the
-   additional commands described under `Commands`_, below.
-
-5. If no scripts were specified, or if ``-i`` or ``--interactive`` was
-   specified, invokes an interactive Bash subshell. The user can use
-   arbitrary Bash commands, plus the additional commands described under
-   `Commands`_, below.
-
-``ovs-sim`` and the sandbox environment that it creates does not require
-superuser or other special privileges.  Generally, it should not be run with
-such privileges.
-
-Options
-=======
-
-.. program: ovs-sim
-
-*script*
-    Runs *script*, which should be a Bash script, within a subshell
-    after initializing.  If multiple script arguments are given, then
-    they are run in the order given.  If any script exits with a
-    nonzero exit code, then ``ovs-sim`` exits immediately with the
-    same exit code.
-
-``-i`` or ``--interactive``
-    By default, if any script is specified, ``ovs-sim`` exits as soon as the
-    scripts finish executing. With this option, or if no scripts are specified,
-    ``ovs-sim`` instead starts an interactive Bash session.
-
-Commands
-========
-
-Scripts and interactive usage may use the following commands
-implemented by ``ovs-sim``.  They are implemented as Bash shell functions
-exported to subshells.
-
-Basic Commands
---------------
-
-These  are  the  basic commands for working with sandboxed Open vSwitch
-instances.
-
-``sim_add`` *sandbox*
-    Starts a new simulated Open vSwitch instance named *sandbox*.
-    Files related to the instance, such as logs, databases, sockets,
-    and pidfiles, are created in a subdirectory also named
-    *sandbox*. Afterward, the ``as`` command (see below) can be used
-    to run Open vSwitch utilities in the context of the new sandbox.
-
-    The new sandbox starts out without any bridges. Use ``ovs-vsctl``
-    in the context of the new sandbox to create a bridge, e.g.::
-
-        sim_add hv0           # Create sandbox hv0.
-        as hv0                # Set hv0 as default sandbox.
-        ovs-vsctl add-br br0  # Add bridge br0 inside hv0.
-
-    The Open vSwitch instances that ``sim_add`` creates enable
-    ``dummy`` devices.  This means that bridges and interfaces can be
-    created with type ``dummy`` to indicate that they should be
-    totally simulated, without any reference to system entities.  In
-    fact, ``ovs-sim`` also configures Open vSwitch so that the default
-    system type of bridges and interfaces are replaced by dummy
-    devices.  Other types of devices, however, retain their usual
-    functions, which means that, e.g., vxlan tunnels still act as
-    tunnels (refer to the documentation).
-
-``as`` *sandbox*
-    Sets sandbox as the default simulation target for Open vSwitch
-    commands (e.g. ``ovs-vsctl``, ``ovs-ofctl``, ``ovs-appctl``).
-
-    This command updates the beginning of the shell prompt to indicate
-    the new default target.
-
-``as`` *sandbox* *command* *arg*...
-    Runs the given command with *sandbox* as the simulation target,
-    e.g.  ``as hv0 ovs-vsctl add-br br0`` runs ``ovs-vsctl add-br
-    br0`` within sandbox ``hv0``.  The default target is unchanged.
-
-Interconnection Network Commands
---------------------------------
-
-When multiple sandboxed Open vSwitch instances exist, one will
-inevitably want to connect them together.  These commands allow for
-that.  Conceptually, an interconnection network is a switch that
-``ovs-sim`` makes it easy to plug into other switches in other
-sandboxed Open vSwitch instances.  Interconnection networks are
-implemented as bridges in the ``main`` switch that ``ovs-sim`` creates
-by default, so to use interconnection networks please avoid working
-with ``main`` directly.
-
-``net_add`` *network*
-    Creates a new interconnection network named *network*.
-
-``net_attach`` *network* *bridge*
-    Adds a new port to *bridge* in the default sandbox (as set with
-    ``as``) and plugs it into interconnection network *network*, which
-    must already have been created by a previous invocation of
-    ``net_add``. The default sandbox must not be ``main``.
-
-OVN Commands
-------------
-
-These commands interact with OVN, the Open Virtual Network.
-
-``ovn_start`` [*options*]
-    Creates and initializes the central OVN databases (both
-    ``ovn-sb(5)`` and ``ovn-nb(5)``) and starts an instance of
-    ``ovsdb-server`` for each one.  Also starts an instance of
-    ``ovn-northd``.
-
-    The following options are available:
-
-       ``--nbdb-model`` *model*
-           Uses the given database model for the northbound database.
-           The *model* may be ``standalone`` (the default), ``backup``,
-           or ``clustered``.
-
-       ``--nbdb-servers`` *n*
-           For a clustered northbound database, the number of servers in
-           the cluster.  The default is 3.
-
-       ``--sbdb-model`` *model*
-           Uses the given database model for the southbound database.
-           The *model* may be ``standalone`` (the default), ``backup``,
-           or ``clustered``.
-
-       ``--sbdb-servers`` *n*
-           For a clustered southbound database, the number of servers in
-           the cluster.  The default is 3.
-
-``ovn_attach`` *network* *bridge* *ip* [*masklen*]
-    First, this command attaches bridge to interconnection network
-    network, just like ``net_attach`` *network* *bridge*.  Second, it
-    configures (simulated) IP address *ip* (with network mask length
-    *masklen*, which defaults to 24) on *bridge*. Finally, it
-    configures the Open vSwitch database to work with OVN and starts
-    ``ovn-controller``.
-
-Examples
-========
-
-The following creates a pair of Open vSwitch instances ``hv0`` and
-``hv1``, adds a port named ``vif0`` or ``vif1``, respectively, to each
-one, and then connects the two through an interconnection network
-``n1``::
-
-    net_add n1
-    for i in 0 1; do
-        sim_add hv$i
-        as hv$i ovs-vsctl add-br br0 -- add-port br0 vif$i
-        as hv$i net_attach n1 br0
-    done
-
-Here’s an extended version that also starts OVN::
-
-    ovn_start
-    ovn-nbctl ls-add lsw0
-    net_add n1
-    for i in 0 1; do
-        sim_add hv$i
-        as hv$i
-        ovs-vsctl add-br br-phys
-        ovn_attach n1 br-phys 192.168.0.`expr $i + 1`
-        ovs-vsctl add-port br-int vif$i -- set Interface vif$i external-ids:iface-id=lp$i
-        ovn-nbctl lsp-add lsw0 lp$i
-        ovn-nbctl lsp-set-addresses lp$i f0:00:00:00:00:0$i
-    done
-
-Here’s a primitive OVN "scale test" (adjust the scale by changing
-``n`` in the first line::
-
-    n=200; export n
-    ovn_start --sbdb-model=clustered
-    net_add n1
-    ovn-nbctl ls-add br0
-    for i in `seq $n`; do
-        (sim_add hv$i
-        as hv$i
-        ovs-vsctl add-br br-phys
-        y=$(expr $i / 256)
-        x=$(expr $i % 256)
-        ovn_attach n1 br-phys 192.168.$y.$x
-        ovs-vsctl add-port br-int vif$i -- set Interface vif$i external-ids:iface-id=lp$i) &
-        case $i in
-            *50|*00) echo $i; wait ;;
-        esac
-    done
-    wait
-    for i in `seq $n`; do
-        yy=$(printf %02x $(expr $i / 256))
-        xx=$(printf $02x $(expr $i % 256))
-        ovn-nbctl lsp-add br0 lp$i
-        ovn-nbctl lsp-set-addresses lp$i f0:00:00:00:$yy:$xx
-    done
-
-When the scale test has finished initializing, you can watch the
-logical ports come up with a command like this::
-
-    watch 'for i in `seq $n`; do if test `ovn-nbctl lsp-get-up lp$i` != up; then echo $i; fi; done'
diff --git a/Makefile.am b/Makefile.am
index 33c18c5d8..88ede2d82 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -173,6 +173,7 @@ SUFFIXES += .in
 	    -e 's,[@]DBDIR[@],$(DBDIR),g' \
 	    -e 's,[@]PYTHON[@],$(PYTHON),g' \
 	    -e 's,[@]OVN_RUNDIR[@],$(OVN_RUNDIR),g' \
+	    -e 's,[@]OVSBUILDDIR[@],$(OVSBUILDDIR),g' \
 	    -e 's,[@]VERSION[@],$(VERSION),g' \
 	    -e 's,[@]localstatedir[@],$(localstatedir),g' \
 	    -e 's,[@]pkgdatadir[@],$(pkgdatadir),g' \
diff --git a/utilities/.gitignore b/utilities/.gitignore
index faaa85ee9..ab063fa04 100644
--- a/utilities/.gitignore
+++ b/utilities/.gitignore
@@ -12,3 +12,4 @@
 /ovn-docker-overlay-driver
 /ovn-docker-underlay-driver
 /ovn-lib
+/ovn-sim
diff --git a/utilities/automake.mk b/utilities/automake.mk
index 197cc7011..bf9388192 100644
--- a/utilities/automake.mk
+++ b/utilities/automake.mk
@@ -52,7 +52,11 @@ CLEANFILES += \
     utilities/ovn-detrace.1 \
     utilities/ovn-detrace \
     utilities/ovn-appctl.8 \
-    utilities/ovn-appctl
+    utilities/ovn-appctl \
+    utilities/ovn-sim
+
+EXTRA_DIST += utilities/ovn-sim.in
+noinst_SCRIPTS += utilities/ovn-sim
 
 utilities/ovn-lib: $(top_builddir)/config.status
 
diff --git a/utilities/ovn-sim.in b/utilities/ovn-sim.in
new file mode 100755
index 000000000..c7a86d8a4
--- /dev/null
+++ b/utilities/ovn-sim.in
@@ -0,0 +1,308 @@
+#! /usr/bin/env bash
+#
+# Copyright (c) 2019 Nicira, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -e
+
+ovn_sim_builddir='@abs_builddir@'; export ovn_sim_builddir
+ovn_sim_srcdir='@abs_top_srcdir@'; export ovn_sim_srcdir
+ovs_sim_builddir='@OVSBUILDDIR@'
+
+# Check that we've got proper builddir and srcdir.
+if test ! -e "$ovs_sim_builddir"/utilities/ovs-sim; then
+    echo "$ovs_sim_builddir/utilities/ovs-sim does not exist ($0 requires ovs-sim)" >&2
+    exit 1
+fi
+if test ! -e "$ovn_sim_builddir"/northd/ovn-northd; then
+    echo "$ovn_sim_builddir/northd/ovn-northd does not exist (need to run \"make\"?)" >&2
+    exit 1
+fi
+if test ! -e "$ovn_sim_srcdir"/README.rst; then
+    echo "$ovn_sim_srcdir/README.rst does not exist" >&2
+    exit 1
+fi
+
+# Put built tools early in $PATH.
+PATH=$ovn_sim_builddir/controller:$ovn_sim_builddir/northd:$ovn_sim_builddir/utilities:$PATH
+export PATH
+
+ovn-nbctl () { command ovn-nbctl -vsyslog:off "$@"; }; export -f ovn-nbctl
+ovn-sbctl () { command ovn-sbctl -vsyslog:off "$@"; }; export -f ovn-sbctl
+
+ovn_start_db() {
+    local db=$1 model=$2 servers=$3 schema=$4
+    local DB=$(echo $db | tr a-z A-Z)
+    local schema_name=$(ovsdb-tool schema-name $schema)
+
+    case $model in
+        standalone | backup) ;;
+        clustered)
+            case $servers in
+                [1-9] | [1-9][0-9]) ;;
+                *) echo "${db}db servers must be between 1 and 99" >&2
+                   exit 1
+                   ;;
+            esac
+            ;;
+        *)
+            echo "unknown ${db}db model \"$model\"" >&2
+            exit 1
+            ;;
+    esac
+
+    ovn_start_ovsdb_server() {
+        local i=$1; shift
+        as ${db}$i ovsdb-server --detach --no-chdir --pidfile=$db.pid \
+           -vsyslog:off -vconsole:off --log-file="$sim_base"/$db$i/$db.log \
+           --remote=db:$schema_name,${DB}_Global,connections \
+           --private-key=db:$schema_name,SSL,private_key \
+           --certificate=db:$schema_name,SSL,certificate \
+           --ca-cert=db:$schema_name,SSL,ca_cert \
+           --ssl-protocols=db:$schema_name,SSL,ssl_protocols \
+           --ssl-ciphers=db:$schema_name,SSL,ssl_ciphers \
+           --unixctl=${db} --remote=punix:$db.ovsdb \
+           "$sim_base"/$db$i/$db.db "$@"
+    }
+
+    ovn_prep_db() {
+        local i=$1
+        mkdir "$sim_base"/${db}$i
+        touch "$sim_base"/${db}$i/.$db.db.~lock~
+    }
+
+    local n_remotes=1
+    case $model in
+        standalone)
+            ovn_prep_db 1
+            ovsdb-tool create "$sim_base"/${db}1/$db.db "$schema"
+            ovn_start_ovsdb_server 1
+            ;;
+        backup)
+            for i in 1 2; do
+                ovn_prep_db $i
+                ovsdb-tool create "$sim_base"/$db$i/$db.db "$schema"
+            done
+            ovn_start_ovsdb_server 1
+            ovn_start_ovsdb_server 2 --sync-from=unix:"$sim_base"/${db}1/$db.ovsdb
+            cat <<EOF
+The backup server of OVN $DB can be accessed by:
+* ovn-${db}ctl --db=unix:$sim_base/${db}2/$db.ovsdb
+* ovs-appctl -t $sim_base/${db}2/${db}
+The backup database file is $sim_base/${db}2/$db.db
+EOF
+            ;;
+        clustered)
+            n_remotes=$servers
+            for i in $(seq $servers); do
+                ovn_prep_db $i
+                if test $i = 1; then
+                    ovsdb-tool create-cluster "$sim_base"/$db$i/$db.db "$schema" unix:"$sim_base"/$db$i/db.raft
+                else
+                    ovsdb-tool join-cluster "$sim_base"/$db$i/$db.db $schema_name unix:"$sim_base"/$db$i/db.raft unix:"$sim_base"/${db}1/db.raft
+                fi
+                ovn_start_ovsdb_server $i
+            done
+            for i in $(seq $servers); do
+                ovsdb-client wait unix:"$sim_base"/${db}$i/$db.ovsdb $schema_name connected
+            done
+            ;;
+    esac
+
+    remote=unix:"$sim_base"/${db}1/$db.ovsdb
+    for i in `seq 2 $n_remotes`; do
+        remote=$remote,unix:"$sim_base"/${db}$i/$db.ovsdb
+    done
+    eval OVN_${DB}_DB=\$remote
+    eval export OVN_${DB}_DB
+}
+export -f ovn_start_db
+
+ovn_start() {
+    local nbdb_model=standalone
+    local nbdb_servers=3
+    local sbdb_model=standalone
+    local sbdb_servers=3
+    local prev=
+    for option; do
+        # This option-parsing mechanism borrowed from a Autoconf-generated
+        # configure script under the following license:
+
+        # Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
+        # 2002, 2003, 2004, 2005, 2006, 2009, 2013 Free Software Foundation, Inc.
+        # This configure script is free software; the Free Software Foundation
+        # gives unlimited permission to copy, distribute and modify it.
+
+        # If the previous option needs an argument, assign it.
+        if test -n "$prev"; then
+            eval $prev=\$option
+            prev=
+            continue
+        fi
+        case $option in
+            *=*) optarg=`expr "X$option" : '[^=]*=\(.*\)'` ;;
+            *) optarg=yes ;;
+        esac
+
+        case $dashdash$option in
+            --)
+                dashdash=yes ;;
+            -h|--help)
+                cat <<EOF
+$FUNCNAME: start OVN central databases and daemons
+usage: $FUNCNAME [OPTION...]
+
+This creates and initializes the central OVN databases (northbound and
+southbound), starts their ovsdb-server daemons, and starts the ovn-northd
+daemon.
+
+Options:
+  --nbdb-model=standalone|backup|clustered    northbound database model
+  --nbdb-servers=N     number of servers in nbdb cluster (default: 3)
+  --sbdb-model=standalone|backup|clustered    southbound database model
+  --sbdb-servers=N     number of servers in sbdb cluster (default: 3)
+  -h, --help           Print this usage message.
+EOF
+                return
+                ;;
+
+            --nbdb-s*=*)
+                nbdb_servers=$optarg
+                nbdb_model=clustered
+                ;;
+            --nbdb-s*)
+                prev=nbdb_servers
+                nbdb_model=clustered
+                ;;
+            --nbdb-m*=*)
+                nbdb_model=$optarg
+                ;;
+            --nbdb-m*)
+                prev=nbdb_model
+                ;;
+            --sbdb-s*=*)
+                sbdb_servers=$optarg
+                sbdb_model=clustered
+                ;;
+            --sbdb-s*)
+                prev=sbdb_servers
+                sbdb_model=clustered
+                ;;
+            --sbdb-m*=*)
+                sbdb_model=$optarg
+                ;;
+            --sbdb-m*)
+                prev=sbdb_model
+                ;;
+            -*)
+                echo "unrecognized option $option (use --help for help)" >&2
+                return 1
+                ;;
+            *)
+                echo "$option: non-option arguments not supported (use --help for help)" >&2
+                return 1
+                ;;
+        esac
+        shift
+    done
+
+    if test -d ovn-sb || test -d ovn-nb; then
+        echo >&2 "OVN already started"
+        return 1
+    fi
+
+    ovn_sim_setvars $sandbox
+
+    # Build ovn man pages as part of ovn_start
+    ovn_man_pages
+
+    ovn_start_db nb "$nbdb_model" "$nbdb_servers" "$ovn_sim_srcdir"/ovn-nb.ovsschema
+    ovn_start_db sb "$sbdb_model" "$sbdb_servers" "$ovn_sim_srcdir"/ovn-sb.ovsschema
+
+    ovn-nbctl init
+    ovn-sbctl init
+
+    mkdir "$sim_base"/northd
+    as northd ovn-northd --detach --no-chdir --pidfile=ovn-northd.pid -vconsole:off \
+       --log-file=ovn-northd.log -vsyslog:off \
+       --ovnnb-db="$OVN_NB_DB" --ovnsb-db="$OVN_SB_DB"
+}
+export -f ovn_start
+
+ovn_attach() {
+    if test "$1" == --help; then
+        cat <<EOF
+$FUNCNAME: attach default sandbox to an interconnection network for OVN
+usage: $FUNCNAME NETWORK BRIDGE IP [MASKLEN]
+
+This starts by doing everything that net_attach does.  Then it configures the
+specified IP and MASKLEN (e.g. 192.168.0.1 and 24) on BRIDGE and starts
+and configures ovn-controller.
+
+MASKLEN defaults to 24 if it is not specified.
+EOF
+        return 0
+    fi
+    if test $# != 3 && test $# != 4; then
+        echo >&2 "$FUNCNAME: wrong number of arguments (use --help for help)"
+        return 1
+    fi
+
+    local net=$1 bridge=$2 ip=$3 masklen=${4-24}
+    net_attach $net $bridge || return $?
+
+    ovn_sim_setvars $sandbox
+
+    ovs-appctl netdev-dummy/ip4addr $bridge $ip/$masklen >/dev/null
+    ovs-appctl ovs/route/add $ip/$masklen $bridge > /dev/null
+    ovs-vsctl \
+        -- set Open_vSwitch . external-ids:system-id=$sandbox \
+        -- set Open_vSwitch . external-ids:ovn-remote=$OVN_SB_DB \
+        -- set Open_vSwitch . external-ids:ovn-encap-type=geneve \
+        -- set Open_vSwitch . external-ids:ovn-encap-ip=$ip\
+        -- add-br br-int \
+        -- set bridge br-int fail-mode=secure other-config:disable-in-band=true
+    ovn-controller --detach --no-chdir -vsyslog:off -vconsole:off \
+                   --log-file=ovn-controller.${sandbox}.log \
+                   --pidfile=ovn-controller.${sandbox}.pid 
+}
+export -f ovn_attach
+
+ovn_sim_setvars() {
+    OVN_RUNDIR=$sim_base/$1; export OVN_RUNDIR
+    OVN_LOGDIR=$sim_base/$1; export OVN_LOGDIR
+    OVN_DBDIR=$sim_base/$1; export OVN_DBDIR
+    OVN_SYSCONFDIR=$sim_base/$1; export OVN_SYSCONFDIR
+}
+export -f ovn_sim_setvars
+
+ovn_as() {
+    if test -n "$1"; then
+        ovn_sim_setvars $1
+    fi
+    as $@
+}
+export -f ovn_as
+
+ovn_man_pages() {
+    # Easy access to OVN manpages.
+    mkdir -p $sim_base/man
+    mandir=`cd $sim_base/man && pwd`
+    (cd "$ovn_sim_builddir" && ${MAKE-make} install-man install-man-rst mandir=$mandir EXTRA_RST_MANPAGES=ovn-sim.1.rst >/dev/null)
+    # Note: MANPATH expected to be already exported by ovs-sim
+    #MANPATH=$mandir:; export MANPATH
+}
+export -f ovn_man_pages
+
+source ${ovs_sim_builddir}/utilities/ovs-sim
