diff mbox series

[ovs-dev,branch-21.12,v2] controller: make garp_max_timeout configurable

Message ID 3ce58cd40c94534bb64e4fcd18c9c1c990cb2884.1702575463.git.lorenzo.bianconi@redhat.com
State Accepted
Delegated to: Dumitru Ceara
Headers show
Series [ovs-dev,branch-21.12,v2] controller: make garp_max_timeout configurable | expand

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Commit Message

Lorenzo Bianconi Dec. 14, 2023, 5:42 p.m. UTC
When using VLAN backed networks and OVN routers leveraging the
'ovn-chassis-mac-mappings' option for east-west traffic, the eth.src field is
replaced by the chassis mac address in order to not expose the router mac
address from different nodes and confuse the TOR switch. However doing so
the TOR switch is not able to learn the port/mac bindings for routed E/W
traffic and it is force to always flood it. Fix this issue adding the
capability to configure a given timeout for garp sent by ovn-controller
and not disable it after the exponential backoff in order to keep
refreshing the entries in TOR swtich fdb table.
More into about the issue can be found here [0].

[0] https://mail.openvswitch.org/pipermail/ovs-discuss/2020-September/050678.html
Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=2087779

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Acked-by: Ales Musil <amusil@redhat.com>
Signed-off-by: Mark Michelson <mmichels@redhat.com>
---
Changes since v1:
- add missing selftest
---
 NEWS                            |   2 +
 controller/ovn-controller.8.xml |  11 ++++
 controller/ovn-controller.c     |   4 +-
 controller/pinctrl.c            |  76 ++++++++++++++++++-----
 controller/pinctrl.h            |   4 +-
 tests/ovn.at                    | 105 ++++++++++++++++++++++++++++++++
 6 files changed, 186 insertions(+), 16 deletions(-)

Comments

Dumitru Ceara Dec. 15, 2023, 1:51 p.m. UTC | #1
On 12/14/23 18:42, Lorenzo Bianconi wrote:
> When using VLAN backed networks and OVN routers leveraging the
> 'ovn-chassis-mac-mappings' option for east-west traffic, the eth.src field is
> replaced by the chassis mac address in order to not expose the router mac
> address from different nodes and confuse the TOR switch. However doing so
> the TOR switch is not able to learn the port/mac bindings for routed E/W
> traffic and it is force to always flood it. Fix this issue adding the
> capability to configure a given timeout for garp sent by ovn-controller
> and not disable it after the exponential backoff in order to keep
> refreshing the entries in TOR swtich fdb table.
> More into about the issue can be found here [0].
> 
> [0] https://mail.openvswitch.org/pipermail/ovs-discuss/2020-September/050678.html
> Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=2087779
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
> Acked-by: Ales Musil <amusil@redhat.com>
> Signed-off-by: Mark Michelson <mmichels@redhat.com>
> ---
> Changes since v1:
> - add missing selftest
> ---

Hi Lorenzo,

Thanks for the backport.

[...]

> diff --git a/tests/ovn.at b/tests/ovn.at
> index 003bf45d5..987e043df 100644
> --- a/tests/ovn.at
> +++ b/tests/ovn.at
> @@ -30762,3 +30762,108 @@ check test "$current_id" = "$prev_id"
>  OVN_CLEANUP([hv1],[hv2])
>  AT_CLEANUP
>  ])
> +
> +OVN_FOR_EACH_NORTHD([
> +AT_SETUP([send gratuitous arp for l3gateway only on selected chassis])

This test is identical to what 77ec310dda51 ("pinctrl.c: Send GARP only
on chassis atached to l3gw") added to branch 22.03.  However, we don't
have the changes that 77ec310dda51 added to pinctrl.c.

Does that mean this test is flaky and might fail occasionally?  Or is it
just that the test doesn't test the change it was supposed to test?

In any case, why not add a new test, just for garp_max_timeout, for main
branch?  We can backport that one alone to all branches, including 21.12.

Thanks,
Dumitru
Lorenzo Bianconi Dec. 15, 2023, 5:07 p.m. UTC | #2
> On 12/14/23 18:42, Lorenzo Bianconi wrote:
> > When using VLAN backed networks and OVN routers leveraging the
> > 'ovn-chassis-mac-mappings' option for east-west traffic, the eth.src field is
> > replaced by the chassis mac address in order to not expose the router mac
> > address from different nodes and confuse the TOR switch. However doing so
> > the TOR switch is not able to learn the port/mac bindings for routed E/W
> > traffic and it is force to always flood it. Fix this issue adding the
> > capability to configure a given timeout for garp sent by ovn-controller
> > and not disable it after the exponential backoff in order to keep
> > refreshing the entries in TOR swtich fdb table.
> > More into about the issue can be found here [0].
> > 
> > [0] https://mail.openvswitch.org/pipermail/ovs-discuss/2020-September/050678.html
> > Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=2087779
> > 
> > Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
> > Acked-by: Ales Musil <amusil@redhat.com>
> > Signed-off-by: Mark Michelson <mmichels@redhat.com>
> > ---
> > Changes since v1:
> > - add missing selftest
> > ---
> 
> Hi Lorenzo,
> 
> Thanks for the backport.
> 
> [...]
> 
> > diff --git a/tests/ovn.at b/tests/ovn.at
> > index 003bf45d5..987e043df 100644
> > --- a/tests/ovn.at
> > +++ b/tests/ovn.at
> > @@ -30762,3 +30762,108 @@ check test "$current_id" = "$prev_id"
> >  OVN_CLEANUP([hv1],[hv2])
> >  AT_CLEANUP
> >  ])
> > +
> > +OVN_FOR_EACH_NORTHD([
> > +AT_SETUP([send gratuitous arp for l3gateway only on selected chassis])
> 
> This test is identical to what 77ec310dda51 ("pinctrl.c: Send GARP only
> on chassis atached to l3gw") added to branch 22.03.  However, we don't
> have the changes that 77ec310dda51 added to pinctrl.c.
> 
> Does that mean this test is flaky and might fail occasionally?  Or is it
> just that the test doesn't test the change it was supposed to test?
> 
> In any case, why not add a new test, just for garp_max_timeout, for main
> branch?  We can backport that one alone to all branches, including 21.12.
> 
> Thanks,
> Dumitru
> 
> 

Hi Dumitru,

Regarding the self-test for 21.12 backport I posted a standalone test for
garp-max-timeout we can easily backport on 21.12.

https://patchwork.ozlabs.org/project/ovn/patch/3957de4e1a47075fd8251156c01ec06cad9ba60a.1702659678.git.lorenzo.bianconi@redhat.com/

Regards,
Lorenzo
Dumitru Ceara Jan. 9, 2024, 9:18 p.m. UTC | #3
On Fri, Dec 15, 2023 at 6:07 PM Lorenzo Bianconi
<lorenzo.bianconi@redhat.com> wrote:
>
> > On 12/14/23 18:42, Lorenzo Bianconi wrote:
> > > When using VLAN backed networks and OVN routers leveraging the
> > > 'ovn-chassis-mac-mappings' option for east-west traffic, the eth.src field is
> > > replaced by the chassis mac address in order to not expose the router mac
> > > address from different nodes and confuse the TOR switch. However doing so
> > > the TOR switch is not able to learn the port/mac bindings for routed E/W
> > > traffic and it is force to always flood it. Fix this issue adding the
> > > capability to configure a given timeout for garp sent by ovn-controller
> > > and not disable it after the exponential backoff in order to keep
> > > refreshing the entries in TOR swtich fdb table.
> > > More into about the issue can be found here [0].
> > >
> > > [0] https://mail.openvswitch.org/pipermail/ovs-discuss/2020-September/050678.html
> > > Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=2087779
> > >
> > > Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
> > > Acked-by: Ales Musil <amusil@redhat.com>
> > > Signed-off-by: Mark Michelson <mmichels@redhat.com>
> > > ---
> > > Changes since v1:
> > > - add missing selftest
> > > ---
> >
> > Hi Lorenzo,
> >
> > Thanks for the backport.
> >
> > [...]
> >
> > > diff --git a/tests/ovn.at b/tests/ovn.at
> > > index 003bf45d5..987e043df 100644
> > > --- a/tests/ovn.at
> > > +++ b/tests/ovn.at
> > > @@ -30762,3 +30762,108 @@ check test "$current_id" = "$prev_id"
> > >  OVN_CLEANUP([hv1],[hv2])
> > >  AT_CLEANUP
> > >  ])
> > > +
> > > +OVN_FOR_EACH_NORTHD([
> > > +AT_SETUP([send gratuitous arp for l3gateway only on selected chassis])
> >
> > This test is identical to what 77ec310dda51 ("pinctrl.c: Send GARP only
> > on chassis atached to l3gw") added to branch 22.03.  However, we don't
> > have the changes that 77ec310dda51 added to pinctrl.c.
> >
> > Does that mean this test is flaky and might fail occasionally?  Or is it
> > just that the test doesn't test the change it was supposed to test?
> >
> > In any case, why not add a new test, just for garp_max_timeout, for main
> > branch?  We can backport that one alone to all branches, including 21.12.
> >
> > Thanks,
> > Dumitru
> >
> >
>
> Hi Dumitru,
>

Hi Lorenzo,

> Regarding the self-test for 21.12 backport I posted a standalone test for
> garp-max-timeout we can easily backport on 21.12.
>
> https://patchwork.ozlabs.org/project/ovn/patch/3957de4e1a47075fd8251156c01ec06cad9ba60a.1702659678.git.lorenzo.bianconi@redhat.com/
>

Thanks, with that one I also pushed this patch to 21.12. I also had to
the bump OVS submodule (cherry picked from 22.03) to make sure our CI
is green.

Regards,
Dumitru
diff mbox series

Patch

diff --git a/NEWS b/NEWS
index 4c300ebc1..69ae85635 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,8 @@  OVN v21.12.3 - xx xxx xxxx
   - A new ACL option, "log-related" has been added that allows for reply and
     related traffic to be logged for an ACL in addition to the traffic that
     directly matches the ACL.
+  - Add "garp-max-timeout-sec" config option to vswitchd external-ids to
+    cap the time between when ovn-controller sends gARP packets.
 
 OVN v21.12.2 - 03 Jun 2022
 --------------------------
diff --git a/controller/ovn-controller.8.xml b/controller/ovn-controller.8.xml
index 68e7de2d4..cb54862bf 100644
--- a/controller/ovn-controller.8.xml
+++ b/controller/ovn-controller.8.xml
@@ -338,6 +338,17 @@ 
         of how many entries there are in the cache.  By default this is set to
         30000 (30 seconds).
       </dd>
+      <dt><code>external_ids:garp-max-timeout-sec</code></dt>
+      <dd>
+        When used, this configuration value specifies the maximum timeout
+        (in seconds) between two consecutive GARP packets sent by
+        <code>ovn-controller</code>.
+        <code>ovn-controller</code> by default sends just 4 GARP packets
+        with an exponential backoff timeout.
+        Setting <code>external_ids:garp-max-timeout-sec</code> allows to
+        cap for the exponential backoff used by <code>ovn-controller</code>
+        to send GARPs packets.
+      </dd>
     </dl>
 
     <p>
diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c
index 797222895..671485a47 100644
--- a/controller/ovn-controller.c
+++ b/controller/ovn-controller.c
@@ -3888,7 +3888,9 @@  main(int argc, char *argv[])
                                     &runtime_data->local_datapaths,
                                     &runtime_data->active_tunnels,
                                     &runtime_data->local_active_ports_ipv6_pd,
-                                    &runtime_data->local_active_ports_ras);
+                                    &runtime_data->local_active_ports_ras,
+                                    ovsrec_open_vswitch_table_get(
+                                            ovs_idl_loop.idl));
                         stopwatch_stop(PINCTRL_RUN_STOPWATCH_NAME,
                                        time_msec());
                         /* Updating monitor conditions if runtime data or
diff --git a/controller/pinctrl.c b/controller/pinctrl.c
index 499da59da..829a22aa3 100644
--- a/controller/pinctrl.c
+++ b/controller/pinctrl.c
@@ -164,6 +164,10 @@  static struct ovs_mutex pinctrl_mutex = OVS_MUTEX_INITIALIZER;
 static struct seq *pinctrl_handler_seq;
 static struct seq *pinctrl_main_seq;
 
+#define GARP_RARP_DEF_MAX_TIMEOUT    16000
+static long long int garp_rarp_max_timeout = GARP_RARP_DEF_MAX_TIMEOUT;
+static bool garp_rarp_continuous;
+
 static void *pinctrl_handler(void *arg);
 
 struct pinctrl {
@@ -209,7 +213,8 @@  static void send_garp_rarp_prepare(
     const struct ovsrec_bridge *,
     const struct sbrec_chassis *,
     const struct hmap *local_datapaths,
-    const struct sset *active_tunnels)
+    const struct sset *active_tunnels,
+    const struct ovsrec_open_vswitch_table *ovs_table)
     OVS_REQUIRES(pinctrl_mutex);
 static void send_garp_rarp_run(struct rconn *swconn,
                                long long int *send_garp_rarp_time)
@@ -3475,7 +3480,8 @@  pinctrl_run(struct ovsdb_idl_txn *ovnsb_idl_txn,
             const struct hmap *local_datapaths,
             const struct sset *active_tunnels,
             const struct shash *local_active_ports_ipv6_pd,
-            const struct shash *local_active_ports_ras)
+            const struct shash *local_active_ports_ras,
+            const struct ovsrec_open_vswitch_table *ovs_table)
 {
     ovs_mutex_lock(&pinctrl_mutex);
     pinctrl_set_br_int_name_(br_int->name);
@@ -3487,7 +3493,7 @@  pinctrl_run(struct ovsdb_idl_txn *ovnsb_idl_txn,
     send_garp_rarp_prepare(ovnsb_idl_txn, sbrec_port_binding_by_datapath,
                            sbrec_port_binding_by_name,
                            sbrec_mac_binding_by_lport_ip, br_int, chassis,
-                           local_datapaths, active_tunnels);
+                           local_datapaths, active_tunnels, ovs_table);
     prepare_ipv6_ras(local_active_ports_ras, sbrec_port_binding_by_name);
     prepare_ipv6_prefixd(ovnsb_idl_txn, sbrec_port_binding_by_name,
                          local_active_ports_ipv6_pd, chassis,
@@ -4330,7 +4336,8 @@  struct garp_rarp_data {
     struct eth_addr ea;          /* Ethernet address of port. */
     ovs_be32 ipv4;               /* Ipv4 address of port. */
     long long int announce_time; /* Next announcement in ms. */
-    int backoff;                 /* Backoff for the next announcement. */
+    int backoff;                 /* Backoff timeout for the next
+                                  * announcement (in msecs). */
     uint32_t dp_key;             /* Datapath used to output this GARP. */
     uint32_t port_key;           /* Port to inject the GARP into. */
 };
@@ -4359,7 +4366,7 @@  add_garp_rarp(const char *name, const struct eth_addr ea, ovs_be32 ip,
     garp_rarp->ea = ea;
     garp_rarp->ipv4 = ip;
     garp_rarp->announce_time = time_msec() + 1000;
-    garp_rarp->backoff = 1;
+    garp_rarp->backoff = 1000; /* msec. */
     garp_rarp->dp_key = dp_key;
     garp_rarp->port_key = port_key;
     shash_add(&send_garp_rarp_data, name, garp_rarp);
@@ -4375,7 +4382,9 @@  send_garp_rarp_update(struct ovsdb_idl_txn *ovnsb_idl_txn,
                       struct ovsdb_idl_index *sbrec_mac_binding_by_lport_ip,
                       const struct hmap *local_datapaths,
                       const struct sbrec_port_binding *binding_rec,
-                      struct shash *nat_addresses)
+                      struct shash *nat_addresses,
+                      long long int garp_max_timeout,
+                      bool garp_continuous)
 {
     volatile struct garp_rarp_data *garp_rarp = NULL;
 
@@ -4401,6 +4410,12 @@  send_garp_rarp_update(struct ovsdb_idl_txn *ovnsb_idl_txn,
                 if (garp_rarp) {
                     garp_rarp->dp_key = binding_rec->datapath->tunnel_key;
                     garp_rarp->port_key = binding_rec->tunnel_key;
+                    if (garp_max_timeout != garp_rarp_max_timeout ||
+                        garp_continuous != garp_rarp_continuous) {
+                        /* reset backoff */
+                        garp_rarp->announce_time = time_msec() + 1000;
+                        garp_rarp->backoff = 1000; /* msec. */
+                    }
                 } else {
                     add_garp_rarp(name, laddrs->ea,
                                   laddrs->ipv4_addrs[i].addr,
@@ -4425,6 +4440,12 @@  send_garp_rarp_update(struct ovsdb_idl_txn *ovnsb_idl_txn,
                     if (garp_rarp) {
                         garp_rarp->dp_key = binding_rec->datapath->tunnel_key;
                         garp_rarp->port_key = binding_rec->tunnel_key;
+                        if (garp_max_timeout != garp_rarp_max_timeout ||
+                            garp_continuous != garp_rarp_continuous) {
+                            /* reset backoff */
+                            garp_rarp->announce_time = time_msec() + 1000;
+                            garp_rarp->backoff = 1000; /* msec. */
+                        }
                     } else {
                         add_garp_rarp(name, laddrs->ea,
                                       0, binding_rec->datapath->tunnel_key,
@@ -4444,6 +4465,12 @@  send_garp_rarp_update(struct ovsdb_idl_txn *ovnsb_idl_txn,
     if (garp_rarp) {
         garp_rarp->dp_key = binding_rec->datapath->tunnel_key;
         garp_rarp->port_key = binding_rec->tunnel_key;
+        if (garp_max_timeout != garp_rarp_max_timeout ||
+            garp_continuous != garp_rarp_continuous) {
+            /* reset backoff */
+            garp_rarp->announce_time = time_msec() + 1000;
+            garp_rarp->backoff = 1000; /* msec. */
+        }
         return;
     }
 
@@ -4529,13 +4556,15 @@  send_garp_rarp(struct rconn *swconn, struct garp_rarp_data *garp_rarp,
     ofpbuf_uninit(&ofpacts);
 
     /* Set the next announcement.  At most 5 announcements are sent for a
-     * vif. */
-    if (garp_rarp->backoff < 16) {
-        garp_rarp->backoff *= 2;
-        garp_rarp->announce_time = current_time + garp_rarp->backoff * 1000;
+     * vif if garp_rarp_max_timeout is not specified otherwise cap the max
+     * timeout to garp_rarp_max_timeout. */
+    if (garp_rarp_continuous || garp_rarp->backoff < garp_rarp_max_timeout) {
+        garp_rarp->announce_time = current_time + garp_rarp->backoff;
     } else {
         garp_rarp->announce_time = LLONG_MAX;
     }
+    garp_rarp->backoff = MIN(garp_rarp_max_timeout, garp_rarp->backoff * 2);
+
     return garp_rarp->announce_time;
 }
 
@@ -5778,13 +5807,26 @@  send_garp_rarp_prepare(struct ovsdb_idl_txn *ovnsb_idl_txn,
                        const struct ovsrec_bridge *br_int,
                        const struct sbrec_chassis *chassis,
                        const struct hmap *local_datapaths,
-                       const struct sset *active_tunnels)
+                       const struct sset *active_tunnels,
+                       const struct ovsrec_open_vswitch_table *ovs_table)
     OVS_REQUIRES(pinctrl_mutex)
 {
     struct sset localnet_vifs = SSET_INITIALIZER(&localnet_vifs);
     struct sset local_l3gw_ports = SSET_INITIALIZER(&local_l3gw_ports);
     struct sset nat_ip_keys = SSET_INITIALIZER(&nat_ip_keys);
     struct shash nat_addresses;
+    unsigned long long garp_max_timeout = GARP_RARP_DEF_MAX_TIMEOUT;
+    bool garp_continuous = false;
+    const struct ovsrec_open_vswitch *cfg =
+        ovsrec_open_vswitch_table_first(ovs_table);
+    if (cfg) {
+        garp_max_timeout = smap_get_ullong(
+                &cfg->external_ids, "garp-max-timeout-sec", 0) * 1000;
+        garp_continuous = !!garp_max_timeout;
+        if (!garp_max_timeout) {
+            garp_max_timeout = GARP_RARP_DEF_MAX_TIMEOUT;
+        }
+    }
 
     shash_init(&nat_addresses);
 
@@ -5813,8 +5855,10 @@  send_garp_rarp_prepare(struct ovsdb_idl_txn *ovnsb_idl_txn,
         const struct sbrec_port_binding *pb = lport_lookup_by_name(
             sbrec_port_binding_by_name, iface_id);
         if (pb) {
-            send_garp_rarp_update(ovnsb_idl_txn, sbrec_mac_binding_by_lport_ip,
-                                  local_datapaths, pb, &nat_addresses);
+            send_garp_rarp_update(ovnsb_idl_txn,
+                                  sbrec_mac_binding_by_lport_ip,
+                                  local_datapaths, pb, &nat_addresses,
+                                  garp_max_timeout, garp_continuous);
         }
     }
 
@@ -5825,7 +5869,8 @@  send_garp_rarp_prepare(struct ovsdb_idl_txn *ovnsb_idl_txn,
             = lport_lookup_by_name(sbrec_port_binding_by_name, gw_port);
         if (pb) {
             send_garp_rarp_update(ovnsb_idl_txn, sbrec_mac_binding_by_lport_ip,
-                                  local_datapaths, pb, &nat_addresses);
+                                  local_datapaths, pb, &nat_addresses,
+                                  garp_max_timeout, garp_continuous);
         }
     }
 
@@ -5843,6 +5888,9 @@  send_garp_rarp_prepare(struct ovsdb_idl_txn *ovnsb_idl_txn,
     shash_destroy(&nat_addresses);
 
     sset_destroy(&nat_ip_keys);
+
+    garp_rarp_max_timeout = garp_max_timeout;
+    garp_rarp_continuous = garp_continuous;
 }
 
 static bool
diff --git a/controller/pinctrl.h b/controller/pinctrl.h
index 88f18e983..b76e43626 100644
--- a/controller/pinctrl.h
+++ b/controller/pinctrl.h
@@ -28,6 +28,7 @@  struct lport_index;
 struct ovsdb_idl_index;
 struct ovsdb_idl_txn;
 struct ovsrec_bridge;
+struct ovsrec_open_vswitch_table;
 struct sbrec_chassis;
 struct sbrec_dns_table;
 struct sbrec_controller_event_table;
@@ -52,7 +53,8 @@  void pinctrl_run(struct ovsdb_idl_txn *ovnsb_idl_txn,
                  const struct hmap *local_datapaths,
                  const struct sset *active_tunnels,
                  const struct shash *local_active_ports_ipv6_pd,
-                 const struct shash *local_active_ports_ras);
+                 const struct shash *local_active_ports_ras,
+                 const struct ovsrec_open_vswitch_table *ovs_table);
 void pinctrl_wait(struct ovsdb_idl_txn *ovnsb_idl_txn);
 void pinctrl_destroy(void);
 void pinctrl_set_br_int_name(char *br_int_name);
diff --git a/tests/ovn.at b/tests/ovn.at
index 003bf45d5..987e043df 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -30762,3 +30762,108 @@  check test "$current_id" = "$prev_id"
 OVN_CLEANUP([hv1],[hv2])
 AT_CLEANUP
 ])
+
+OVN_FOR_EACH_NORTHD([
+AT_SETUP([send gratuitous arp for l3gateway only on selected chassis])
+AT_SKIP_IF([test $HAVE_TCPDUMP = no])
+ovn_start
+
+# Create logical switch
+ovn-nbctl ls-add ls0
+# Create gateway router
+ovn-nbctl lr-add lr0
+# Add router port to gateway router
+ovn-nbctl lrp-add lr0 lr0-ls0 f0:00:00:00:00:01 192.168.0.1/24
+ovn-nbctl lsp-add ls0 ls0-lr0 -- set Logical_Switch_Port ls0-lr0 \
+    type=router options:router-port=lr0-ls0 addresses='"f0:00:00:00:00:01"'
+
+# Create a localnet port.
+ovn-nbctl lsp-add ls0 ln_port
+ovn-nbctl lsp-set-addresses ln_port unknown
+ovn-nbctl lsp-set-type ln_port localnet
+ovn-nbctl --wait=hv lsp-set-options ln_port network_name=physnet1
+
+# Prepare packets
+touch empty_expected
+echo "fffffffffffff0000000000108060001080006040001f00000000001c0a80001000000000000c0a80001" > arp_expected
+
+net_add n1
+sim_add hv1
+as hv1
+ovs-vsctl \
+    -- add-br br-phys \
+    -- add-br br-eth0
+
+ovn_attach n1 br-phys 192.168.0.10
+
+AT_CHECK([ovs-vsctl set Open_vSwitch . external-ids:ovn-bridge-mappings=physnet1:br-eth0])
+AT_CHECK([ovs-vsctl add-port br-eth0 snoopvif -- set Interface snoopvif options:tx_pcap=hv1/snoopvif-tx.pcap options:rxq_pcap=hv1/snoopvif-rx.pcap])
+
+sim_add hv2
+as hv2
+ovs-vsctl \
+    -- add-br br-phys \
+    -- add-br br-eth0
+
+ovn_attach n1 br-phys 192.168.0.20
+
+AT_CHECK([ovs-vsctl set Open_vSwitch . external-ids:ovn-bridge-mappings=physnet1:br-eth0])
+#AT_CHECK([ovs-vsctl add-port br-eth0 snoopvif -- set Interface snoopvif options:tx_pcap=hv2/snoopvif-tx.pcap options:rxq_pcap=hv2/snoopvif-rx.pcap])
+
+ovn-sbctl dump-flows > sbflows
+AT_CAPTURE_FILE([sbflows])
+
+# Wait until the patch ports are created in hv1 and hv2 to connect br-int to br-eth0
+AT_CHECK([ovn-nbctl set logical_router lr0 options:chassis=hv1])
+OVS_WAIT_UNTIL([test 1 = `as hv1 ovs-vsctl show | grep "Port patch-br-int-to-ln_port" | wc -l`])
+
+AT_CHECK([ovn-nbctl set logical_router lr0 options:chassis=hv2])
+OVS_WAIT_UNTIL([test 1 = `as hv2 ovs-vsctl show | grep "Port patch-br-int-to-ln_port" | wc -l`])
+
+# Temporarily remove lr0 chassis
+AT_CHECK([ovn-nbctl remove logical_router lr0 options chassis])
+
+reset_pcap_file() {
+    local hv=$1
+    local iface=$2
+    local pcap_file=$3
+    as $hv
+    ovs-vsctl -- set Interface $iface options:tx_pcap=dummy-tx.pcap \
+options:rxq_pcap=dummy-rx.pcap
+    rm -f ${pcap_file}*.pcap
+    ovs-vsctl -- set Interface $iface options:tx_pcap=${pcap_file}-tx.pcap \
+options:rxq_pcap=${pcap_file}-rx.pcap
+}
+
+reset_pcap_file hv1 snoopvif hv1/snoopvif
+reset_pcap_file hv2 snoopvif hv2/snoopvif
+
+hv1_uuid=$(ovn-sbctl --bare --columns _uuid list chassis hv1)
+AT_CHECK([ovn-nbctl set logical_router lr0 options:chassis=hv1])
+OVS_WAIT_UNTIL([
+    ls0_lr0=$(ovn-sbctl --bare --columns chassis list port_binding ls0-lr0)
+    test "$ls0_lr0" = $hv1_uuid
+])
+
+sleep 2
+OVN_CHECK_PACKETS_CONTAIN([hv1/snoopvif-tx.pcap], [arp_expected])
+OVN_CHECK_PACKETS([hv2/snoopvif-tx.pcap], [empty_expected])
+
+# Temporarily remove lr0 chassis
+AT_CHECK([ovn-nbctl remove logical_router lr0 options chassis])
+as hv1 reset_pcap_file snoopvif hv1/snoopvif
+as hv2 reset_pcap_file snoopvif hv2/snoopvif
+
+AT_CHECK([ovn-nbctl --wait=hv set logical_router lr0 options:chassis=hv1])
+# set garp max timeout to 2s
+AT_CHECK([as hv1 ovs-vsctl set Open_vSwitch . external-ids:garp-max-timeout-sec=2])
+
+OVS_WAIT_UNTIL([
+n_arp=$(tcpdump -c 10 -ner hv1/snoopvif-tx.pcap arp | wc -l)
+test "$n_arp" = 10
+])
+
+OVN_CLEANUP([hv1],[hv2])
+
+AT_CLEANUP
+])