[ovs-dev,2/2] ovn: Support a new Logical_Switch_Port.type - 'external'

Message ID 20181005171510.31709-1-nusiddiq@redhat.com
State Superseded
Headers show
Series
  • Addressing VLAN tenant network issues and add
Related show

Commit Message

Numan Siddique Oct. 5, 2018, 5:15 p.m.
From: Numan Siddique <nusiddiq@redhat.com>

In the case of OpenStack + OVN, when the VMs are booted on
hypervisors supporting SR-IOV nics, there are no OVS ports
for these VMs. When these VMs sends DHCPv4, DHPCv6 or IPv6
Router Solicitation requests, the local ovn-controller
cannot reply to these packets. OpenStack Neutron dhcp agent
service needs to be run to serve these requests.

With the new logical port type - 'external', OVN itself can
handle these requests avoiding the need to deploy any
external services like neutron dhcp agent.

To make use of this feature, CMS has to
 - create a logical port for such VMs
 - set the type to 'external'
 - set requested-chassis="<chassis-name>" in the options
   column.
 - create a localnet port for the logical switch
 - configure the ovn-bridge-mappings option in the OVS db.

When the ovn-controller running in that 'chassis', detects
the Port_Binding row, it adds the necessary DHCPv4/v6 OF
flows. Since the packet enters the logical switch pipeline
via the localnet port, the inport register (reg14) is set
to the tunnel key of localnet port in the match conditions.

In case the chassis goes down for some reason, it is the
responsibility of CMS to change the 'requested-chassis'
option to some other active chassis, so that it can serve
these requests.

When the VM with the external port, sends an ARP request for
the router ips, only the chassis which has claimed the port,
will reply to the ARP requests. Rest of the chassis on
receiving these packets drop them in the ingress switch
datapath stage - S_SWITCH_IN_EXTERNAL_PORT which is just
before S_SWITCH_IN_L2_LKUP.

This would guarantee that only the chassis which has claimed
the external ports will run the router datapath pipeline.

Signed-off-by: Numan Siddique <nusiddiq@redhat.com>
---
 ovn/controller/binding.c        |  15 +-
 ovn/controller/lflow.c          |  41 ++-
 ovn/controller/lflow.h          |   2 +
 ovn/controller/lport.c          |  26 ++
 ovn/controller/lport.h          |   5 +
 ovn/controller/ovn-controller.c |   6 +
 ovn/lib/ovn-util.c              |   1 +
 ovn/northd/ovn-northd.8.xml     |  52 +++-
 ovn/northd/ovn-northd.c         | 123 ++++++--
 ovn/ovn-architecture.7.xml      |  66 ++++
 ovn/ovn-nb.xml                  |  33 ++
 tests/ovn.at                    | 530 +++++++++++++++++++++++++++++++-
 12 files changed, 868 insertions(+), 32 deletions(-)

Patch

diff --git a/ovn/controller/binding.c b/ovn/controller/binding.c
index 021ecddcf..ee396c93d 100644
--- a/ovn/controller/binding.c
+++ b/ovn/controller/binding.c
@@ -471,13 +471,26 @@  consider_local_datapath(struct ovsdb_idl_txn *ovnsb_idl_txn,
          * for them. */
         sset_add(local_lports, binding_rec->logical_port);
         our_chassis = false;
+    } else if (!strcmp(binding_rec->type, "external")) {
+        const char *chassis_id = smap_get(&binding_rec->options,
+                                          "requested-chassis");
+        our_chassis = chassis_id && (
+            !strcmp(chassis_id, chassis_rec->name) ||
+            !strcmp(chassis_id, chassis_rec->hostname));
+        if (our_chassis) {
+            add_local_datapath(sbrec_datapath_binding_by_key,
+                               sbrec_port_binding_by_datapath,
+                               sbrec_port_binding_by_name,
+                               binding_rec->datapath, true, local_datapaths);
+        }
     }
 
     if (our_chassis
         || !strcmp(binding_rec->type, "patch")
         || !strcmp(binding_rec->type, "localport")
         || !strcmp(binding_rec->type, "vtep")
-        || !strcmp(binding_rec->type, "localnet")) {
+        || !strcmp(binding_rec->type, "localnet")
+        || !strcmp(binding_rec->type, "external")) {
         update_local_lport_ids(local_lport_ids, binding_rec);
     }
 
diff --git a/ovn/controller/lflow.c b/ovn/controller/lflow.c
index 8db81927e..98e8ed3b9 100644
--- a/ovn/controller/lflow.c
+++ b/ovn/controller/lflow.c
@@ -52,7 +52,10 @@  lflow_init(void)
 struct lookup_port_aux {
     struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath;
     struct ovsdb_idl_index *sbrec_port_binding_by_name;
+    struct ovsdb_idl_index *sbrec_port_binding_by_type;
+    struct ovsdb_idl_index *sbrec_datapath_binding_by_key;
     const struct sbrec_datapath_binding *dp;
+    const struct sbrec_chassis *chassis;
 };
 
 struct condition_aux {
@@ -66,6 +69,8 @@  static void consider_logical_flow(
     struct ovsdb_idl_index *sbrec_chassis_by_name,
     struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath,
     struct ovsdb_idl_index *sbrec_port_binding_by_name,
+    struct ovsdb_idl_index *sbrec_port_binding_by_type,
+    struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
     const struct sbrec_logical_flow *,
     const struct hmap *local_datapaths,
     const struct sbrec_chassis *,
@@ -89,8 +94,24 @@  lookup_port_cb(const void *aux_, const char *port_name, unsigned int *portp)
     const struct sbrec_port_binding *pb
         = lport_lookup_by_name(aux->sbrec_port_binding_by_name, port_name);
     if (pb && pb->datapath == aux->dp) {
-        *portp = pb->tunnel_key;
-        return true;
+        if (strcmp(pb->type, "external")) {
+            *portp = pb->tunnel_key;
+            return true;
+        }
+        const char *chassis_id = smap_get(&pb->options,
+                                          "requested-chassis");
+        if (chassis_id && (!strcmp(chassis_id, aux->chassis->name) ||
+                           !strcmp(chassis_id, aux->chassis->hostname))) {
+            const struct sbrec_port_binding *localnet_pb
+                = lport_lookup_by_type(aux->sbrec_datapath_binding_by_key,
+                                       aux->sbrec_port_binding_by_type,
+                                       aux->dp->tunnel_key, "localnet");
+            if (localnet_pb) {
+                *portp = localnet_pb->tunnel_key;
+                return true;
+            }
+        }
+        return false;
     }
 
     const struct sbrec_multicast_group *mg = mcgroup_lookup_by_dp_name(
@@ -144,6 +165,8 @@  add_logical_flows(
     struct ovsdb_idl_index *sbrec_chassis_by_name,
     struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath,
     struct ovsdb_idl_index *sbrec_port_binding_by_name,
+    struct ovsdb_idl_index *sbrec_port_binding_by_type,
+    struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
     const struct sbrec_dhcp_options_table *dhcp_options_table,
     const struct sbrec_dhcpv6_options_table *dhcpv6_options_table,
     const struct sbrec_logical_flow_table *logical_flow_table,
@@ -183,6 +206,8 @@  add_logical_flows(
         consider_logical_flow(sbrec_chassis_by_name,
                               sbrec_multicast_group_by_name_datapath,
                               sbrec_port_binding_by_name,
+                              sbrec_port_binding_by_type,
+                              sbrec_datapath_binding_by_key,
                               lflow, local_datapaths,
                               chassis, &dhcp_opts, &dhcpv6_opts, &nd_ra_opts,
                               addr_sets, port_groups, active_tunnels,
@@ -200,6 +225,8 @@  consider_logical_flow(
     struct ovsdb_idl_index *sbrec_chassis_by_name,
     struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath,
     struct ovsdb_idl_index *sbrec_port_binding_by_name,
+    struct ovsdb_idl_index *sbrec_port_binding_by_type,
+    struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
     const struct sbrec_logical_flow *lflow,
     const struct hmap *local_datapaths,
     const struct sbrec_chassis *chassis,
@@ -292,7 +319,10 @@  consider_logical_flow(
         .sbrec_multicast_group_by_name_datapath
             = sbrec_multicast_group_by_name_datapath,
         .sbrec_port_binding_by_name = sbrec_port_binding_by_name,
-        .dp = lflow->logical_datapath
+        .sbrec_port_binding_by_type = sbrec_port_binding_by_type,
+        .sbrec_datapath_binding_by_key = sbrec_datapath_binding_by_key,
+        .dp = lflow->logical_datapath,
+        .chassis = chassis
     };
     struct condition_aux cond_aux = {
         .sbrec_chassis_by_name = sbrec_chassis_by_name,
@@ -463,6 +493,8 @@  void
 lflow_run(struct ovsdb_idl_index *sbrec_chassis_by_name,
           struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath,
           struct ovsdb_idl_index *sbrec_port_binding_by_name,
+          struct ovsdb_idl_index *sbrec_port_binding_by_type,
+          struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
           const struct sbrec_dhcp_options_table *dhcp_options_table,
           const struct sbrec_dhcpv6_options_table *dhcpv6_options_table,
           const struct sbrec_logical_flow_table *logical_flow_table,
@@ -481,7 +513,8 @@  lflow_run(struct ovsdb_idl_index *sbrec_chassis_by_name,
 
     add_logical_flows(sbrec_chassis_by_name,
                       sbrec_multicast_group_by_name_datapath,
-                      sbrec_port_binding_by_name, dhcp_options_table,
+                      sbrec_port_binding_by_name, sbrec_port_binding_by_type,
+                      sbrec_datapath_binding_by_key, dhcp_options_table,
                       dhcpv6_options_table, logical_flow_table,
                       local_datapaths, chassis, addr_sets, port_groups,
                       active_tunnels, local_lport_ids, flow_table, group_table,
diff --git a/ovn/controller/lflow.h b/ovn/controller/lflow.h
index d19338140..b2911e0eb 100644
--- a/ovn/controller/lflow.h
+++ b/ovn/controller/lflow.h
@@ -68,6 +68,8 @@  void lflow_init(void);
 void lflow_run(struct ovsdb_idl_index *sbrec_chassis_by_name,
                struct ovsdb_idl_index *sbrec_multicast_group_by_name_datapath,
                struct ovsdb_idl_index *sbrec_port_binding_by_name,
+               struct ovsdb_idl_index *sbrec_port_binding_by_type,
+               struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
                const struct sbrec_dhcp_options_table *,
                const struct sbrec_dhcpv6_options_table *,
                const struct sbrec_logical_flow_table *,
diff --git a/ovn/controller/lport.c b/ovn/controller/lport.c
index cc5c5fbb2..9c827d9b0 100644
--- a/ovn/controller/lport.c
+++ b/ovn/controller/lport.c
@@ -64,6 +64,32 @@  lport_lookup_by_key(struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
     return retval;
 }
 
+const struct sbrec_port_binding *
+lport_lookup_by_type(struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
+                     struct ovsdb_idl_index *sbrec_port_binding_by_type,
+                     uint64_t dp_key, const char *port_type)
+{
+    /* Lookup datapath corresponding to dp_key. */
+    const struct sbrec_datapath_binding *db = datapath_lookup_by_key(
+        sbrec_datapath_binding_by_key, dp_key);
+    if (!db) {
+        return NULL;
+    }
+
+    /* Build key for an indexed lookup. */
+    struct sbrec_port_binding *pb = sbrec_port_binding_index_init_row(
+            sbrec_port_binding_by_type);
+    sbrec_port_binding_index_set_datapath(pb, db);
+    sbrec_port_binding_index_set_type(pb, port_type);
+
+    const struct sbrec_port_binding *retval = sbrec_port_binding_index_find(
+            sbrec_port_binding_by_type, pb);
+
+    sbrec_port_binding_index_destroy_row(pb);
+
+    return retval;
+}
+
 const struct sbrec_datapath_binding *
 datapath_lookup_by_key(struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
                        uint64_t dp_key)
diff --git a/ovn/controller/lport.h b/ovn/controller/lport.h
index 7dcd5bee0..2d49792f6 100644
--- a/ovn/controller/lport.h
+++ b/ovn/controller/lport.h
@@ -42,6 +42,11 @@  const struct sbrec_port_binding *lport_lookup_by_key(
     struct ovsdb_idl_index *sbrec_port_binding_by_key,
     uint64_t dp_key, uint64_t port_key);
 
+const struct sbrec_port_binding *lport_lookup_by_type(
+    struct ovsdb_idl_index *sbrec_datapath_binding_by_key,
+    struct ovsdb_idl_index *sbrec_port_binding_by_type,
+    uint64_t dp_key, const char *port_type);
+
 const struct sbrec_datapath_binding *datapath_lookup_by_key(
     struct ovsdb_idl_index *sbrec_datapath_binding_by_key, uint64_t dp_key);
 
diff --git a/ovn/controller/ovn-controller.c b/ovn/controller/ovn-controller.c
index f46156021..60f305cd6 100644
--- a/ovn/controller/ovn-controller.c
+++ b/ovn/controller/ovn-controller.c
@@ -145,6 +145,7 @@  update_sb_monitors(struct ovsdb_idl *ovnsb_idl,
      * ports that have a Gateway_Chassis that point's to our own
      * chassis */
     sbrec_port_binding_add_clause_type(&pb, OVSDB_F_EQ, "chassisredirect");
+    sbrec_port_binding_add_clause_type(&pb, OVSDB_F_EQ, "external");
     if (chassis) {
         /* This should be mostly redundant with the other clauses for port
          * bindings, but it allows us to catch any ports that are assigned to
@@ -616,6 +617,9 @@  main(int argc, char *argv[])
     struct ovsdb_idl_index *sbrec_port_binding_by_datapath
         = ovsdb_idl_index_create1(ovnsb_idl_loop.idl,
                                   &sbrec_port_binding_col_datapath);
+    struct ovsdb_idl_index *sbrec_port_binding_by_type
+        = ovsdb_idl_index_create1(ovnsb_idl_loop.idl,
+                                  &sbrec_port_binding_col_type);
     struct ovsdb_idl_index *sbrec_datapath_binding_by_key
         = ovsdb_idl_index_create1(ovnsb_idl_loop.idl,
                                   &sbrec_datapath_binding_col_tunnel_key);
@@ -742,6 +746,8 @@  main(int argc, char *argv[])
                             sbrec_chassis_by_name,
                             sbrec_multicast_group_by_name_datapath,
                             sbrec_port_binding_by_name,
+                            sbrec_port_binding_by_type,
+                            sbrec_datapath_binding_by_key,
                             sbrec_dhcp_options_table_get(ovnsb_idl_loop.idl),
                             sbrec_dhcpv6_options_table_get(ovnsb_idl_loop.idl),
                             sbrec_logical_flow_table_get(ovnsb_idl_loop.idl),
diff --git a/ovn/lib/ovn-util.c b/ovn/lib/ovn-util.c
index e9464e926..0e4439c5d 100644
--- a/ovn/lib/ovn-util.c
+++ b/ovn/lib/ovn-util.c
@@ -311,6 +311,7 @@  static const char *OVN_NB_LSP_TYPES[] = {
     "localport",
     "router",
     "vtep",
+    "external",
 };
 
 bool
diff --git a/ovn/northd/ovn-northd.8.xml b/ovn/northd/ovn-northd.8.xml
index f52699bd3..c133969ed 100644
--- a/ovn/northd/ovn-northd.8.xml
+++ b/ovn/northd/ovn-northd.8.xml
@@ -113,6 +113,26 @@ 
         logical ports on which port security is not enabled, these advance all
         packets that match the <code>inport</code>.
       </li>
+
+      <li>
+        <p>
+          For each logical port of type <code>external</code> with port
+          security enabled and the logical switch to which it belongs, has a
+          localnet port, a priority 90 flow is added which matches on the
+          <code>inport</code> of localnet port and the valid
+          <code>eth.src</code> address(es) of the <code>external</code>
+          logical port and sets the <code>REGBIT_EXT_PORT_NOT_RESIDENT</code>
+          flag if the logical port doesn't reside on a chassis and advances the
+          packet to the next flow table.
+        </p>
+
+        <p>
+          On the chassis where the <code>external</code> port resides doesn't
+          add the above flow. The priority 50 flow with the match on the
+          <code>inport</code> of the localnet port takes care of forwarding
+          the packet to the next flow table.
+        </p>
+      </li>
     </ul>
 
     <p>
@@ -626,7 +646,8 @@  nd_na_router {
     <p>
       This table adds the DHCPv4 options to a DHCPv4 packet from the
       logical ports configured with IPv4 address(es) and DHCPv4 options,
-      and similarly for DHCPv6 options.
+      and similarly for DHCPv6 options. This table also adds flows for the
+      logical ports of type <code>external</code>.
     </p>
 
     <ul>
@@ -827,7 +848,34 @@  output;
       </li>
     </ul>
 
-    <h3>Ingress Table 16 Destination Lookup</h3>
+    <h3>Ingress table 16 External ports</h3>
+
+    <p>
+      Traffic from the <code>external</code> logical ports enter the ingress
+      datapath pipeline via the <code>localnet</code> port. This table adds the
+      below logical flows to handle the traffic from these ports.
+    </p>
+
+    <ul>
+      <li>
+        <p>
+          For each router port IP address <code>A</code> which belongs to the
+          logical switch, A priority-100 flow is added which matches
+          <code>REGBIT_EXT_PORT_NOT_RESIDENT &amp;&amp; arp.tpa == <var>A</var>
+          &amp;&amp; arp.op == 1</code> (ARP request to the router
+          IP) with the action to <code>drop</code> the packet.
+        </p>
+
+        <p>
+          These flows guarantees that the ARP/NS request to the router IP
+          address from the external ports is responded by only the chassis
+          which has claimed these external ports. All the other chassis,
+          drops these packets.
+        </p>
+      </li>
+    </ul>
+
+    <h3>Ingress Table 17 Destination Lookup</h3>
 
     <p>
       This table implements switching behavior.  It contains these logical
diff --git a/ovn/northd/ovn-northd.c b/ovn/northd/ovn-northd.c
index 3998a898c..42832dbc7 100644
--- a/ovn/northd/ovn-northd.c
+++ b/ovn/northd/ovn-northd.c
@@ -118,7 +118,8 @@  enum ovn_stage {
     PIPELINE_STAGE(SWITCH, IN,  DHCP_RESPONSE, 13, "ls_in_dhcp_response") \
     PIPELINE_STAGE(SWITCH, IN,  DNS_LOOKUP,    14, "ls_in_dns_lookup")    \
     PIPELINE_STAGE(SWITCH, IN,  DNS_RESPONSE,  15, "ls_in_dns_response")  \
-    PIPELINE_STAGE(SWITCH, IN,  L2_LKUP,       16, "ls_in_l2_lkup")       \
+    PIPELINE_STAGE(SWITCH, IN,  EXTERNAL_PORT, 16, "ls_in_external_port") \
+    PIPELINE_STAGE(SWITCH, IN,  L2_LKUP,       17, "ls_in_l2_lkup")       \
                                                                           \
     /* Logical switch egress stages. */                                   \
     PIPELINE_STAGE(SWITCH, OUT, PRE_LB,       0, "ls_out_pre_lb")         \
@@ -165,12 +166,13 @@  enum ovn_stage {
 #define OVN_ACL_PRI_OFFSET 1000
 
 /* Register definitions specific to switches. */
-#define REGBIT_CONNTRACK_DEFRAG  "reg0[0]"
-#define REGBIT_CONNTRACK_COMMIT  "reg0[1]"
-#define REGBIT_CONNTRACK_NAT     "reg0[2]"
-#define REGBIT_DHCP_OPTS_RESULT  "reg0[3]"
-#define REGBIT_DNS_LOOKUP_RESULT "reg0[4]"
-#define REGBIT_ND_RA_OPTS_RESULT "reg0[5]"
+#define REGBIT_CONNTRACK_DEFRAG         "reg0[0]"
+#define REGBIT_CONNTRACK_COMMIT         "reg0[1]"
+#define REGBIT_CONNTRACK_NAT            "reg0[2]"
+#define REGBIT_DHCP_OPTS_RESULT         "reg0[3]"
+#define REGBIT_DNS_LOOKUP_RESULT        "reg0[4]"
+#define REGBIT_ND_RA_OPTS_RESULT        "reg0[5]"
+#define REGBIT_EXT_PORT_NOT_RESIDENT    "reg0[6]"
 
 /* Register definitions for switches and routers. */
 #define REGBIT_NAT_REDIRECT     "reg9[0]"
@@ -442,6 +444,8 @@  struct ovn_datapath {
 
     /* Port groups related to the datapath, used only when nbs is NOT NULL. */
     struct hmap nb_pgs;
+
+    bool has_external_ports;
 };
 
 struct macam_node {
@@ -1581,6 +1585,10 @@  join_logical_ports(struct northd_context *ctx,
                    od->localnet_port = op;
                 }
 
+                if (!strcmp(nbsp->type, "external")) {
+                   od->has_external_ports = true;
+                }
+
                 op->lsp_addrs
                     = xmalloc(sizeof *op->lsp_addrs * nbsp->n_addresses);
                 for (size_t j = 0; j < nbsp->n_addresses; j++) {
@@ -2870,6 +2878,12 @@  lsp_is_up(const struct nbrec_logical_switch_port *lsp)
     return !lsp->up || *lsp->up;
 }
 
+static bool
+lsp_is_external(const struct nbrec_logical_switch_port *nbsp)
+{
+    return !strcmp(nbsp->type, "external");
+}
+
 static bool
 build_dhcpv4_action(struct ovn_port *op, ovs_be32 offer_ip,
                     struct ds *options_action, struct ds *response_action,
@@ -4051,9 +4065,24 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
             continue;
         }
 
+        bool is_external = lsp_is_external(op->nbsp);
+        if (is_external && (!op->od->localnet_port || !op->n_ps_addrs)) {
+            /* If the lsp is external with no port securty addresses then,
+             * we don't need to add any port security rules.
+             * The packets from external ports is received on localnet port
+             * and we allow the traffic from localnet ports.
+             *
+             * We also need to ignore these ports if the logical switch
+             * doesn't have a localnet port.
+             */
+            continue;
+        }
+
         ds_clear(&match);
         ds_clear(&actions);
-        ds_put_format(&match, "inport == %s", op->json_key);
+        ds_put_format(
+            &match, "inport == %s",
+            is_external ? op->od->localnet_port->json_key : op->json_key);
         build_port_security_l2("eth.src", op->ps_addrs, op->n_ps_addrs,
                                &match);
 
@@ -4061,11 +4090,21 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
         if (queue_id) {
             ds_put_format(&actions, "set_queue(%s); ", queue_id);
         }
+
+        if (is_external) {
+            /* Set REGBIT_EXT_PORT_NOT_RESIDENT bit if the external port
+             * doesn't reside on a chassis. */
+            ds_put_format(&match, " && !is_chassis_resident(%s)",
+                          op->json_key);
+            ds_put_cstr(&actions, REGBIT_EXT_PORT_NOT_RESIDENT" = 1; ");
+        }
+
         ds_put_cstr(&actions, "next;");
-        ovn_lflow_add(lflows, op->od, S_SWITCH_IN_PORT_SEC_L2, 50,
+        ovn_lflow_add(lflows, op->od, S_SWITCH_IN_PORT_SEC_L2,
+                      is_external ? 90 : 50,
                       ds_cstr(&match), ds_cstr(&actions));
 
-        if (op->nbsp->n_port_security) {
+        if (op->nbsp->n_port_security && !is_external) {
             build_port_security_ip(P_IN, op, lflows);
             build_port_security_nd(op, lflows);
         }
@@ -4113,7 +4152,7 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
          *  - port type is localport
          */
         if (!lsp_is_up(op->nbsp) && strcmp(op->nbsp->type, "router") &&
-            strcmp(op->nbsp->type, "localport")) {
+            strcmp(op->nbsp->type, "localport") && lsp_is_external(op->nbsp)) {
             continue;
         }
 
@@ -4225,6 +4264,13 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
             continue;
         }
 
+        bool is_external = lsp_is_external(op->nbsp);
+        if (is_external && !op->od->localnet_port) {
+            /* If it's an external port and there is no localnet port
+             * ignore it. */
+            continue;
+        }
+
         for (size_t i = 0; i < op->n_lsp_addrs; i++) {
             for (size_t j = 0; j < op->lsp_addrs[i].n_ipv4_addrs; j++) {
                 struct ds options_action = DS_EMPTY_INITIALIZER;
@@ -4237,8 +4283,8 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
                     ds_put_format(
                         &match, "inport == %s && eth.src == %s && "
                         "ip4.src == 0.0.0.0 && ip4.dst == 255.255.255.255 && "
-                        "udp.src == 68 && udp.dst == 67", op->json_key,
-                        op->lsp_addrs[i].ea_s);
+                        "udp.src == 68 && udp.dst == 67",
+                        op->json_key, op->lsp_addrs[i].ea_s);
 
                     ovn_lflow_add(lflows, op->od, S_SWITCH_IN_DHCP_OPTIONS,
                                   100, ds_cstr(&match),
@@ -4343,7 +4389,8 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
     /* Ingress table 12 and 13: DHCP options and response, by default goto
      * next. (priority 0).
      * Ingress table 14 and 15: DNS lookup and response, by default goto next.
-     * (priority 0).*/
+     * (priority 0).
+     * Ingress table 16 - External port handling */
 
     HMAP_FOR_EACH (od, key_node, datapaths) {
         if (!od->nbs) {
@@ -4354,9 +4401,47 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
         ovn_lflow_add(lflows, od, S_SWITCH_IN_DHCP_RESPONSE, 0, "1", "next;");
         ovn_lflow_add(lflows, od, S_SWITCH_IN_DNS_LOOKUP, 0, "1", "next;");
         ovn_lflow_add(lflows, od, S_SWITCH_IN_DNS_RESPONSE, 0, "1", "next;");
+        ovn_lflow_add(lflows, od, S_SWITCH_IN_EXTERNAL_PORT, 0, "1", "next;");
+
+        if (od->has_external_ports) {
+            /* Table 16: External port. Drop ARP request for router ips from
+             * external ports if REGBIT_EXT_PORT_NOT_RESIDENT is set.
+             * This makes the router pipeline to be run only the chassis
+             * binding the external ports. */
+            for (size_t i = 0; i < od->n_router_ports; i++) {
+                struct ovn_port *rp = od->router_ports[i];
+                for (size_t j = 0; j < rp->n_lsp_addrs; j++) {
+                    for (size_t k = 0; k < rp->lsp_addrs[j].n_ipv4_addrs;
+                         k++) {
+                        ds_clear(&match);
+                        ds_put_format(
+                            &match, REGBIT_EXT_PORT_NOT_RESIDENT""
+                            " && arp.tpa == %s && arp.op == 1",
+                            rp->lsp_addrs[j].ipv4_addrs[k].addr_s);
+                        ds_clear(&actions);
+                        ovn_lflow_add(lflows, od, S_SWITCH_IN_EXTERNAL_PORT,
+                                      100, ds_cstr(&match), "drop;");
+                    }
+                    for (size_t k = 0; k < rp->lsp_addrs[j].n_ipv6_addrs;
+                         k++) {
+                        ds_clear(&match);
+                        ds_put_format(
+                            &match, REGBIT_EXT_PORT_NOT_RESIDENT""
+                            " && nd_ns && ip6.dst == {%s, %s} && "
+                            "nd.target == %s",
+                            rp->lsp_addrs[j].ipv6_addrs[k].addr_s,
+                            rp->lsp_addrs[j].ipv6_addrs[k].sn_addr_s,
+                            rp->lsp_addrs[j].ipv6_addrs[k].addr_s);
+                        ds_clear(&actions);
+                        ovn_lflow_add(lflows, od, S_SWITCH_IN_EXTERNAL_PORT,
+                                      100, ds_cstr(&match), "drop;");
+                    }
+                }
+            }
+        }
     }
 
-    /* Ingress table 16: Destination lookup, broadcast and multicast handling
+    /* Ingress table 17: Destination lookup, broadcast and multicast handling
      * (priority 100). */
     HMAP_FOR_EACH (op, key_node, ports) {
         if (!op->nbsp) {
@@ -4376,9 +4461,9 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
                       "outport = \""MC_FLOOD"\"; output;");
     }
 
-    /* Ingress table 16: Destination lookup, unicast handling (priority 50), */
+    /* Ingress table 17: Destination lookup, unicast handling (priority 50), */
     HMAP_FOR_EACH (op, key_node, ports) {
-        if (!op->nbsp) {
+        if (!op->nbsp || lsp_is_external(op->nbsp)) {
             continue;
         }
 
@@ -4495,7 +4580,7 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
         }
     }
 
-    /* Ingress table 16: Destination lookup for unknown MACs (priority 0). */
+    /* Ingress table 17: Destination lookup for unknown MACs (priority 0). */
     HMAP_FOR_EACH (od, key_node, datapaths) {
         if (!od->nbs) {
             continue;
@@ -4530,7 +4615,7 @@  build_lswitch_flows(struct hmap *datapaths, struct hmap *ports,
      * Priority 150 rules drop packets to disabled logical ports, so that they
      * don't even receive multicast or broadcast packets. */
     HMAP_FOR_EACH (op, key_node, ports) {
-        if (!op->nbsp) {
+        if (!op->nbsp || lsp_is_external(op->nbsp)) {
             continue;
         }
 
diff --git a/ovn/ovn-architecture.7.xml b/ovn/ovn-architecture.7.xml
index 998470c34..05af5f3f0 100644
--- a/ovn/ovn-architecture.7.xml
+++ b/ovn/ovn-architecture.7.xml
@@ -1627,6 +1627,72 @@ 
     </li>
   </ol>
 
+  <h2>Native OVN services for external logical ports</h2>
+
+  <p>
+    To support OVN native services (like DHCP/IPv6 RA/DNS lookup) to the
+    cloud resources which are external, OVN supports <code>external</code>
+    logical ports.
+  </p>
+
+  <p>
+    Below are some of the use cases where <code>external</code> ports can be
+    used.
+  </p>
+
+  <ul>
+    <li>
+      VMs connected to SR-IOV nics - Traffic from these VMs by passes the
+      kernel stack and local <code>ovn-controller</code> do not bind these
+      ports and cannot serve the native services.
+    </li>
+    <li>
+      When CMS supports provisioning baremetal servers.
+    </li>
+  </ul>
+
+  <p>
+    OVN will provide the native services if CMS has done the below
+    configuration in the <dfn>OVN Northbound Database</dfn>.
+  </p>
+
+  <ul>
+    <li>
+      A row is created in <code>Logical_Switch_Port</code>, configuring the
+      <ref column="addresses" table="Logical_Switch_Port" db="OVN_NB"/> column
+      and setting the <ref column="type" table="Logical_Switch_Port"
+      db="OVN_NB"/> to <code>external</code>.
+    </li>
+
+    <li>
+      <ref column="options:requested-chassis" table="Logical_Switch_Port"
+      db="OVN_NB"/> column is configured to a desired chassis.
+    </li>
+
+    <li>
+      The chassis on which this logical port is requested has the
+      <code>ovn-bridge-mappings</code> configured and has proper L2
+      connectivity so that it can receive the DHCP and other related request
+      packets from these external resources.
+    </li>
+
+    <li>
+      The Logical_Switch of this port has a <code>localnet</code> port.
+    </li>
+
+    <li>
+      Native OVN services are enabled by configuring the DHCP and other
+      options like the way it is done for the normal logical ports.
+    </li>
+  </ul>
+
+  <p>
+    OVN doesn't support HA for these <code>external</code> ports. In case
+    the <code>ovn-controller</code> running on the requested chassis goes down,
+    it is the responsiblity of CMS, to reschedule these <code>external</code>
+    ports to other active chassis.
+  </p>
+
   <h1>Security</h1>
 
   <h2>Role-Based Access Controls for the Soutbound DB</h2>
diff --git a/ovn/ovn-nb.xml b/ovn/ovn-nb.xml
index 13ae56e13..251287702 100644
--- a/ovn/ovn-nb.xml
+++ b/ovn/ovn-nb.xml
@@ -302,6 +302,39 @@ 
           <dd>
             A port to a logical switch on a VTEP gateway.
           </dd>
+
+          <dt><code>external</code></dt>
+          <dd>
+            <p>
+              Represents a logical port which is external and not having
+              an OVS port in the integration bridge.
+              <code>OVN</code> will never receive any traffic from this port or
+              send any traffic to this port. <code>OVN</code> can support
+              native services like DHCPv4/DHCPv6/DNS for this port.
+              If <ref column="options:requested-chassis"/> is defined,
+              <code>ovn-controller</code> running in that chassis will bind
+              this port to provide these native services. It is expected that
+              this port belong to a bridged logical switch
+              (with a <code>localnet</code> port).
+            </p>
+
+            <p>
+              Below are some of the use cases where <code>external</code>
+              ports can be used.
+            </p>
+
+            <ul>
+              <li>
+                VMs connected to SR-IOV nics - Traffic from these VMs by passes
+                the kernel stack and local <code>ovn-controller</code> do not
+                bind these ports and cannot serve the native services.
+              </li>
+
+              <li>
+                When CMS supports provisioning baremetal servers.
+              </li>
+            </ul>
+          </dd>
         </dl>
       </column>
     </group>
diff --git a/tests/ovn.at b/tests/ovn.at
index 504ba228d..fa5ac108e 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -9428,9 +9428,9 @@  AT_CHECK([as hv2 ovs-ofctl dump-flows br-int table=32 | grep active_backup | gre
 sleep 3 # let BFD sessions settle so we get the right flows on the right chassis
 
 # make sure that flows for handling the outside router port reside on gw1
-AT_CHECK([as gw1 ovs-ofctl dump-flows br-int table=24 | grep 00:00:02:01:02:04 | wc -l], [0], [[1
+AT_CHECK([as gw1 ovs-ofctl dump-flows br-int table=25 | grep 00:00:02:01:02:04 | wc -l], [0], [[1
 ]])
-AT_CHECK([as gw2 ovs-ofctl dump-flows br-int table=24 | grep 00:00:02:01:02:04 | wc -l], [0], [[0
+AT_CHECK([as gw2 ovs-ofctl dump-flows br-int table=25 | grep 00:00:02:01:02:04 | wc -l], [0], [[0
 ]])
 
 # make sure ARP responder flows for outside router port reside on gw1 too
@@ -9520,9 +9520,9 @@  AT_CHECK([ovs-vsctl --bare --columns bfd find Interface name=ovn-hv1-0],[0],
 sleep 3  # let BFD sessions settle so we get the right flows on the right chassis
 
 # make sure that flows for handling the outside router port reside on gw2 now
-AT_CHECK([as gw2 ovs-ofctl dump-flows br-int table=24 | grep 00:00:02:01:02:04 | wc -l], [0], [[1
+AT_CHECK([as gw2 ovs-ofctl dump-flows br-int table=25 | grep 00:00:02:01:02:04 | wc -l], [0], [[1
 ]])
-AT_CHECK([as gw1 ovs-ofctl dump-flows br-int table=24 | grep 00:00:02:01:02:04 | wc -l], [0], [[0
+AT_CHECK([as gw1 ovs-ofctl dump-flows br-int table=25 | grep 00:00:02:01:02:04 | wc -l], [0], [[0
 ]])
 
 # disconnect GW2 from the network, GW1 should take over
@@ -9534,9 +9534,9 @@  sleep 4
 bfd_dump
 
 # make sure that flows for handling the outside router port reside on gw2 now
-AT_CHECK([as gw1 ovs-ofctl dump-flows br-int table=24 | grep 00:00:02:01:02:04 | wc -l], [0], [[1
+AT_CHECK([as gw1 ovs-ofctl dump-flows br-int table=25 | grep 00:00:02:01:02:04 | wc -l], [0], [[1
 ]])
-AT_CHECK([as gw2 ovs-ofctl dump-flows br-int table=24 | grep 00:00:02:01:02:04 | wc -l], [0], [[0
+AT_CHECK([as gw2 ovs-ofctl dump-flows br-int table=25 | grep 00:00:02:01:02:04 | wc -l], [0], [[0
 ]])
 
 # check that the chassis redirect port has been reclaimed by the gw1 chassis
@@ -11376,6 +11376,524 @@  as hv2 start_daemon ovn-controller
 OVN_CLEANUP([hv1],[hv2])
 AT_CLEANUP
 
+AT_SETUP([ovn -- external logical port])
+AT_SKIP_IF([test $HAVE_PYTHON = no])
+ovn_start
+
+net_add n1
+sim_add hv1
+sim_add hv2
+
+ovn-nbctl ls-add ls1
+ovn-nbctl lsp-add ls1 ls1-lp1 \
+-- lsp-set-addresses ls1-lp1 "f0:00:00:00:00:01 10.0.0.4 ae70::4"
+
+# Add a couple of external logical port
+ovn-nbctl lsp-add ls1 ls1-lp_ext1 \
+-- lsp-set-addresses ls1-lp_ext1 "f0:00:00:00:00:03 10.0.0.6 ae70::6"
+ovn-nbctl lsp-set-port-security ls1-lp_ext1 \
+"f0:00:00:00:00:03 10.0.0.6 ae70::6"
+ovn-nbctl lsp-set-type ls1-lp_ext1 external
+
+ovn-nbctl lsp-add ls1 ls1-lp_ext2 \
+-- lsp-set-addresses ls1-lp_ext2 "f0:00:00:00:00:04 10.0.0.7 ae70::7"
+ovn-nbctl lsp-set-port-security ls1-lp_ext2 \
+"f0:00:00:00:00:04 10.0.0.7 ae70::8"
+ovn-nbctl lsp-set-type ls1-lp_ext2 external
+
+d1="$(ovn-nbctl create DHCP_Options cidr=10.0.0.0/24 \
+options="\"server_id\"=\"10.0.0.1\" \"server_mac\"=\"ff:10:00:00:00:01\" \
+\"lease_time\"=\"3600\" \"router\"=\"10.0.0.1\"")"
+
+d2="$(ovn-nbctl create DHCP_Options cidr="ae70\:\:/64" \
+options="\"server_id\"=\"00:00:00:10:00:01\"")"
+
+ovn-nbctl lsp-set-dhcpv4-options ls1-lp1 ${d1}
+ovn-nbctl lsp-set-dhcpv4-options ls1-lp_ext1 ${d1}
+ovn-nbctl lsp-set-dhcpv4-options ls1-lp_ext2 ${d1}
+
+ovn-nbctl lsp-set-dhcpv6-options ls1-lp1 ${d2}
+ovn-nbctl lsp-set-dhcpv6-options ls1-lp_ext1 ${d2}
+ovn-nbctl lsp-set-dhcpv6-options ls1-lp_ext2 ${d2}
+
+# Create a logical router and connect it to ls1
+ovn-nbctl lr-add lr0
+ovn-nbctl lrp-add lr0 lr0-ls1 a0:10:00:00:00:01 10.0.0.1/24
+ovn-nbctl lsp-add ls1 ls1-lr0
+ovn-nbctl set Logical_Switch_Port ls1-lr0 type=router \
+    options:router-port=lr0-ls1 addresses=router
+
+as hv1
+ovs-vsctl add-br br-phys
+ovn_attach n1 br-phys 192.168.0.1
+ovs-vsctl -- add-port br-phys hv1-ext1 -- \
+    set interface hv1-ext1 options:tx_pcap=hv1/ext1-tx.pcap \
+    options:rxq_pcap=hv1/ext1-rx.pcap \
+    ofport-request=2
+ovs-vsctl set open . external-ids:ovn-bridge-mappings=phys:br-phys
+
+as hv2
+ovs-vsctl add-br br-phys
+ovn_attach n1 br-phys 192.168.0.2
+ovs-vsctl -- add-port br-phys hv2-ext2 -- \
+    set interface hv2-ext2 options:tx_pcap=hv2/ext2-tx.pcap \
+    options:rxq_pcap=hv2/ext2-rx.pcap \
+    ofport-request=2
+ovs-vsctl set open . external-ids:ovn-bridge-mappings=phys:br-phys
+
+ovn-sbctl dump-flows > lflows_n.txt
+
+# No DHCPv4/v6 flows for the external port - ls1-lp_ext1 - 10.0.0.6 in hv1 and
+# hv2 as requested-chassis option is not set and no localnet port added to ls1.
+AT_CHECK([ovn-sbctl dump-flows ls1 | grep "offerip = 10.0.0.6" | \
+wc -l], [0], [0
+])
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | wc -l], [0], [0
+])
+
+hv1_uuid=$(ovn-sbctl list chassis hv1 | grep uuid | awk '{print $3}')
+
+# The port_binding row for ls1-lp_ext1 should have empty chassis
+chassis=$(ovn-sbctl list port_binding ls1-lp_ext1 | grep -v gateway | \
+grep -v requested | grep chassis | awk '{print $3}')
+
+AT_CHECK([test $chassis == "[[]]"], [0], [])
+
+# Set the requested-chassis option for ls1-lp_ext1
+ovn-nbctl --wait=hv lsp-set-options ls1-lp_ext1 requested-chassis=hv1
+
+# No DHCPv4/v6 flows for the external port - ls1-lp_ext1 - 10.0.0.6 in hv1 and hv2
+# as no localnet port added to ls1 yet.
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | wc -l], [0], [0
+])
+
+# Add the localnet port to the logical switch ls1
+ovn-nbctl lsp-add ls1 ln-public
+ovn-nbctl lsp-set-addresses ln-public unknown
+ovn-nbctl lsp-set-type ln-public localnet
+ovn-nbctl --wait=hv lsp-set-options ln-public network_name=phys
+
+ln_public_key=$(ovn-sbctl list port_binding ln-public | grep  tunnel_key | \
+awk '{print $3}')
+
+# The ls1-lp_ext1 should be bound to hv1
+chassis=$(ovn-sbctl list port_binding ls1-lp_ext1 | grep -v gateway | \
+grep -v requested | grep chassis | awk '{print $3}')
+AT_CHECK([test $chassis == "$hv1_uuid"], [0], [])
+
+# There should be DHCPv4/v6 OF flows for the ls1-lp_ext1 port in hv1
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | grep reg14=0x$ln_public_key | \
+wc -l], [0], [3
+])
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | \
+grep reg14=0x$ln_public_key | wc -l], [0], [1
+])
+
+# There should ne no DHCPv4/v6 flows for ls1-lp_ext1 on hv2
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | wc -l], [0], [0
+])
+
+# No DHCPv4/v6 flows for the external port - ls1-lp_ext2 - 10.0.0.7 in hv1 and
+# hv2 as requested-chassis option is not set.
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.07" | wc -l], [0], [0
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.07" | wc -l], [0], [0
+])
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.07" | wc -l], [0], [0
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.07" | wc -l], [0], [0
+])
+
+as hv1
+ovs-vsctl show
+
+# This shell function sends a DHCP request packet
+# test_dhcp INPORT SRC_MAC DHCP_TYPE OFFER_IP ...
+test_dhcp() {
+    local inport=$1 src_mac=$2 dhcp_type=$3 offer_ip=$4 use_ip=$5
+    shift; shift; shift; shift; shift;
+    if test $use_ip != 0; then
+        src_ip=$1
+        dst_ip=$2
+        shift; shift;
+    else
+        src_ip=`ip_to_hex 0 0 0 0`
+        dst_ip=`ip_to_hex 255 255 255 255`
+    fi
+    local request=ffffffffffff${src_mac}0800451001100000000080110000${src_ip}${dst_ip}
+    # udp header and dhcp header
+    request=${request}0044004300fc0000
+    request=${request}010106006359aa760000000000000000000000000000000000000000${src_mac}
+    # client hardware padding
+    request=${request}00000000000000000000
+    # server hostname
+    request=${request}0000000000000000000000000000000000000000000000000000000000000000
+    request=${request}0000000000000000000000000000000000000000000000000000000000000000
+    # boot file name
+    request=${request}0000000000000000000000000000000000000000000000000000000000000000
+    request=${request}0000000000000000000000000000000000000000000000000000000000000000
+    request=${request}0000000000000000000000000000000000000000000000000000000000000000
+    request=${request}0000000000000000000000000000000000000000000000000000000000000000
+    # dhcp magic cookie
+    request=${request}63825363
+    # dhcp message type
+    request=${request}3501${dhcp_type}ff
+
+    local srv_mac=$1 srv_ip=$2 expected_dhcp_opts=$3
+    # total IP length will be the IP length of the request packet
+    # (which is 272 in our case) + 8 (padding bytes) + (expected_dhcp_opts / 2)
+    ip_len=`expr 280 + ${#expected_dhcp_opts} / 2`
+    udp_len=`expr $ip_len - 20`
+    ip_len=$(printf "%x" $ip_len)
+    udp_len=$(printf "%x" $udp_len)
+    # $ip_len var will be in 3 digits i.e 134. So adding a '0' before $ip_len
+    local reply=${src_mac}${srv_mac}080045100${ip_len}000000008011XXXX${srv_ip}${offer_ip}
+    # udp header and dhcp header.
+    # $udp_len var will be in 3 digits. So adding a '0' before $udp_len
+    reply=${reply}004300440${udp_len}0000020106006359aa760000000000000000
+    # your ip address
+    reply=${reply}${offer_ip}
+    # next server ip address, relay agent ip address, client mac address
+    reply=${reply}0000000000000000${src_mac}
+    # client hardware padding
+    reply=${reply}00000000000000000000
+    # server hostname
+    reply=${reply}0000000000000000000000000000000000000000000000000000000000000000
+    reply=${reply}0000000000000000000000000000000000000000000000000000000000000000
+    # boot file name
+    reply=${reply}0000000000000000000000000000000000000000000000000000000000000000
+    reply=${reply}0000000000000000000000000000000000000000000000000000000000000000
+    reply=${reply}0000000000000000000000000000000000000000000000000000000000000000
+    reply=${reply}0000000000000000000000000000000000000000000000000000000000000000
+    # dhcp magic cookie
+    reply=${reply}63825363
+    # dhcp message type
+    local dhcp_reply_type=02
+    if test $dhcp_type = 03; then
+        dhcp_reply_type=05
+    fi
+    reply=${reply}3501${dhcp_reply_type}${expected_dhcp_opts}00000000ff00000000
+    echo $reply >> ext1_v4.expected
+
+    as hv1 ovs-appctl netdev-dummy/receive hv${inport}-ext${inport} $request
+}
+
+
+trim_zeros() {
+    sed 's/\(00\)\{1,\}$//'
+}
+
+# This shell function sends a DHCPv6 request packet
+# test_dhcpv6 INPORT SRC_MAC SRC_LLA DHCPv6_MSG_TYPE OFFER_IP OUTPORT...
+# The OUTPORTs (zero or more) list the VIFs on which the original DHCPv6
+# packet should be received twice (one from ovn-controller and the other
+# from the "ovs-ofctl monitor br-int resume"
+test_dhcpv6() {
+    local inport=$1 src_mac=$2 src_lla=$3 msg_code=$4 offer_ip=$5
+    local req_pkt_in_expected=$6
+    local request=ffffffffffff${src_mac}86dd00000000002a1101${src_lla}
+    # dst ip ff02::1:2
+    request=${request}ff020000000000000000000000010002
+    # udp header and dhcpv6 header
+    request=${request}02220223002affff${msg_code}010203
+    # Client identifier
+    request=${request}0001000a00030001${src_mac}
+    # IA-NA (Identity Association for Non Temporary Address)
+    request=${request}0003000c0102030400000e1000001518
+    shift; shift; shift; shift; shift;
+
+    local server_mac=000000100001
+    local server_lla=fe80000000000000020000fffe100001
+    local reply_code=07
+    if test $msg_code = 01; then
+        reply_code=02
+    fi
+    local msg_len=54
+    if test $offer_ip = 1; then
+        msg_len=28
+    fi
+    local reply=${src_mac}${server_mac}86dd0000000000${msg_len}1101
+    reply=${reply}${server_lla}${src_lla}
+
+    # udp header and dhcpv6 header
+    reply=${reply}0223022200${msg_len}ffff${reply_code}010203
+    # Client identifier
+    reply=${reply}0001000a00030001${src_mac}
+    # IA-NA
+    if test $offer_ip != 1; then
+        reply=${reply}0003002801020304ffffffffffffffff00050018${offer_ip}
+        reply=${reply}ffffffffffffffff
+    fi
+    # Server identifier
+    reply=${reply}0002000a00030001${server_mac}
+
+    echo $reply | trim_zeros >> ext${inport}_v6.expected
+    # The inport also receives the request packet since it is connected
+    # to the br-phys.
+    #echo $request >> ext${inport}_v6.expected
+
+    as hv1 ovs-appctl netdev-dummy/receive hv${inport}-ext${inport} $request
+}
+
+reset_pcap_file() {
+    local iface=$1
+    local pcap_file=$2
+    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=${pcap_file}-rx.pcap
+}
+
+ip_to_hex() {
+    printf "%02x%02x%02x%02x" "$@"
+}
+
+AT_CAPTURE_FILE([ofctl_monitor0_hv1.log])
+as hv1 ovs-ofctl monitor br-int resume --detach --no-chdir \
+--pidfile=ovs-ofctl0.pid 2> ofctl_monitor0_hv1.log
+
+AT_CAPTURE_FILE([ofctl_monitor0_hv2.log])
+as hv2 ovs-ofctl monitor br-int resume --detach --no-chdir \
+--pidfile=ovs-ofctl0.pid 2> ofctl_monitor0_hv2.log
+
+# Send DHCPDISCOVER.
+offer_ip=`ip_to_hex 10 0 0 6`
+server_ip=`ip_to_hex 10 0 0 1`
+server_mac=ff1000000001
+expected_dhcp_opts=330400000e100104ffffff0003040a00000136040a000001
+test_dhcp 1 f00000000003 01 $offer_ip 0 $server_mac $server_ip \
+$expected_dhcp_opts
+
+# NXT_RESUMEs should be 1 in hv1.
+OVS_WAIT_UNTIL([test 1 = `cat ofctl_monitor0_hv1.log | grep -c NXT_RESUME`])
+
+# NXT_RESUMEs should be 0 in hv2.
+OVS_WAIT_UNTIL([test 0 = `cat ofctl_monitor0_hv2.log | grep -c NXT_RESUME`])
+
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/ext1-tx.pcap > ext1_v4.packets
+cat ext1_v4.expected | cut -c -48 > expout
+AT_CHECK([cat ext1_v4.packets | cut -c -48], [0], [expout])
+# Skipping the IPv4 checksum.
+cat ext1_v4.expected | cut -c 53- > expout
+AT_CHECK([cat ext1_v4.packets | cut -c 53-], [0], [expout])
+
+# ovs-ofctl also resumes the packets and this causes other ports to receive
+# the DHCP request packet. So reset the pcap files so that its easier to test.
+reset_pcap_file hv1-ext1 hv1/ext1
+rm -f ext1_v4.expected
+rm -f ext1_v4.packets
+
+# Send DHCPv6 request
+src_mac=f00000000003
+src_lla=fe80000000000000f20000fffe000003
+offer_ip=ae700000000000000000000000000006
+test_dhcpv6 1 $src_mac $src_lla 01 $offer_ip
+
+# NXT_RESUMEs should be 2 in hv1.
+OVS_WAIT_UNTIL([test 2 = `cat ofctl_monitor0_hv1.log | grep -c NXT_RESUME`])
+
+# NXT_RESUMEs should be 0 in hv2.
+OVS_WAIT_UNTIL([test 0 = `cat ofctl_monitor0_hv2.log | grep -c NXT_RESUME`])
+
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/ext1-tx.pcap | \
+sort > ext1_v6.packets
+cat ext1_v6.expected | cut -c -120 > expout
+AT_CHECK([cat ext1_v6.packets | cut -c -120], [0], [expout])
+# Skipping the UDP checksum
+cat ext1_v6.expected | cut -c 125- > expout
+AT_CHECK([cat ext1_v6.packets | cut -c 125-], [0], [expout])
+
+rm -f ext1_v6.expected
+rm -f ext1_v6.packets
+reset_pcap_file hv1-ext1 hv1/ext1
+
+# Change the requested-chassis option for ls1-lp_ext1 from hv1 to hv2
+ovn-nbctl --wait=hv lsp-set-options ls1-lp_ext1 requested-chassis=hv2
+
+hv2_uuid=$(ovn-sbctl list chassis hv2 | grep uuid | awk '{print $3}')
+
+# The ls1-lp_ext1 should be bound to hv2
+chassis=$(ovn-sbctl list port_binding ls1-lp_ext1 | grep -v gateway | \
+grep -v requested | grep chassis | awk '{print $3}')
+AT_CHECK([test $chassis == "$hv2_uuid"], [0], [])
+
+# There should be OF flows for DHCP4/v6 for the ls1-lp_ext1 port in hv2
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | grep reg14=0x$ln_public_key | \
+wc -l], [0], [3
+])
+AT_CHECK([as hv2 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | \
+grep reg14=0x$ln_public_key | wc -l], [0], [1
+])
+
+# There should ne no DHCPv4/v6 flows for ls1-lp_ext1 on hv1
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep "0a.00.00.06" | wc -l], [0], [0
+])
+AT_CHECK([as hv1 ovs-ofctl dump-flows br-int | grep table=20 | \
+grep controller | grep tp_src=546 | grep \
+"ae.70.00.00.00.00.00.00.00.00.00.00.00.00.00.06" | \
+grep reg14=0x$ln_public_key | wc -l], [0], [0
+])
+
+# Send DHCPDISCOVER again for hv1/ext1. The DHCP response should come from
+# hv2 ovn-controller. Due to the test setup, the port hv1/ext1 is also
+# receiving the expected packet.
+offer_ip=`ip_to_hex 10 0 0 6`
+server_ip=`ip_to_hex 10 0 0 1`
+server_mac=ff1000000001
+expected_dhcp_opts=330400000e100104ffffff0003040a00000136040a000001
+test_dhcp 1 f00000000003 01 $offer_ip 0 $server_mac $server_ip \
+$expected_dhcp_opts
+
+# NXT_RESUMEs should be 2 in hv1.
+OVS_WAIT_UNTIL([test 2 = `cat ofctl_monitor0_hv1.log | grep -c NXT_RESUME`])
+
+# NXT_RESUMEs should be 1 in hv2.
+OVS_WAIT_UNTIL([test 1 = `cat ofctl_monitor0_hv2.log | grep -c NXT_RESUME`])
+
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/ext1-tx.pcap > ext1_v4.packets
+cat ext1_v4.expected | cut -c -48 > expout
+AT_CHECK([cat ext1_v4.packets | cut -c -48], [0], [expout])
+# Skipping the IPv4 checksum.
+cat ext1_v4.expected | cut -c 53- > expout
+AT_CHECK([cat ext1_v4.packets | cut -c 53-], [0], [expout])
+
+# ovs-ofctl also resumes the packets and this causes other ports to receive
+# the DHCP request packet. So reset the pcap files so that its easier to test.
+reset_pcap_file hv1-ext1 hv1/ext1
+rm -f ext1_v4.expected
+
+# Send DHCPv6 request again
+src_mac=f00000000003
+src_lla=fe80000000000000f20000fffe000003
+offer_ip=ae700000000000000000000000000006
+test_dhcpv6 1 $src_mac $src_lla 01 $offer_ip 1
+
+# NXT_RESUMEs should be 2 in hv1.
+OVS_WAIT_UNTIL([test 2 = `cat ofctl_monitor0_hv1.log | grep -c NXT_RESUME`])
+
+# NXT_RESUMEs should be 2 in hv2.
+OVS_WAIT_UNTIL([test 2 = `cat ofctl_monitor0_hv2.log | grep -c NXT_RESUME`])
+
+as hv1
+ovs-vsctl show
+ovs-ofctl dump-flows br-int
+
+as hv2
+ovs-vsctl show
+ovs-ofctl dump-flows br-int
+
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/ext1-tx.pcap | \
+sort > ext1_v6.packets
+cat ext1_v6.expected | cut -c -120 > expout
+AT_CHECK([cat ext1_v6.packets | cut -c -120], [0], [expout])
+# Skipping the UDP checksum
+cat ext1_v6.expected | cut -c 125- > expout
+AT_CHECK([cat ext1_v6.packets | cut -c 125-], [0], [expout])
+
+rm -f ext1_v6.expected
+rm -f ext1_v6.packets
+
+as hv1
+ovs-vsctl show
+reset_pcap_file hv1-ext1 hv1/ext1
+reset_pcap_file br-phys_n1 hv1/br-phys_n1
+reset_pcap_file br-phys hv1/br-phys
+
+as hv2
+ovs-vsctl show
+reset_pcap_file hv2-ext2 hv2/ext2
+reset_pcap_file br-phys_n1 hv2/br-phys_n1
+reset_pcap_file br-phys hv2/br-phys
+
+# From  ls1-lp_ext1, send ARP request for the router ip. The ARP
+# response should come from the router pipeline of hv2.
+ext1_mac=f00000000003
+router_mac=a01000000001
+ext1_ip=`ip_to_hex 10 0 0 6`
+router_ip=`ip_to_hex 10 0 0 1`
+arp_request=ffffffffffff${ext1_mac}08060001080006040001${ext1_mac}${ext1_ip}000000000000${router_ip}
+
+as hv1 ovs-appctl netdev-dummy/receive hv1-ext1 $arp_request
+expected_response=${src_mac}${router_mac}08060001080006040002${router_mac}${router_ip}${ext1_mac}${ext1_ip}
+echo $expected_response > expout
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/ext1-tx.pcap > ext1_arp_resp
+AT_CHECK([cat ext1_arp_resp], [0], [expout])
+
+# Verify that the response came from hv2
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv2/br-phys_n1-tx.pcap > ext1_arp_resp
+AT_CHECK([cat ext1_arp_resp], [0], [expout])
+
+
+# # Change the requested-chassis option for ls1-lp_ext1 from hv2 to hv1
+ovn-nbctl --wait=hv lsp-set-options ls1-lp_ext1 requested-chassis=hv1
+
+as hv1
+ovs-vsctl show
+reset_pcap_file hv1-ext1 hv1/ext1
+reset_pcap_file br-phys_n1 hv1/br-phys_n1
+reset_pcap_file br-phys hv1/br-phys
+
+as hv2
+ovs-vsctl show
+reset_pcap_file hv2-ext2 hv2/ext2
+reset_pcap_file br-phys_n1 hv2/br-phys_n1
+reset_pcap_file br-phys hv2/br-phys
+
+as hv1 ovs-appctl netdev-dummy/receive hv1-ext1 $arp_request
+
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv1/ext1-tx.pcap > ext1_arp_resp
+AT_CHECK([cat ext1_arp_resp], [0], [expout])
+
+# Verify that the response didn't come from hv2
+$PYTHON "$top_srcdir/utilities/ovs-pcap.in" hv2/br-phys_n1-tx.pcap > ext1_arp_resp
+AT_CHECK([cat ext1_arp_resp], [0], [])
+
+OVN_CLEANUP([hv1],[hv2])
+AT_CLEANUP
+
 AT_SETUP([ovn -- ovn-controller restart])
 AT_SKIP_IF([test $HAVE_PYTHON = no])
 ovn_start