diff --git a/NEWS b/NEWS
index 0ec0c71b1b8..196e5838f4b 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,8 @@ Post-v3.4.0
       $ ovs-vsctl set Bridge br0 flow_tables:0=@N -- \
           --id=@N create Flow_Table \
                     name=table0 prefixes=nw_dst,nw_src,ipv6_dst,ipv6_src
+   - Address prefix tracking is now enabled by default for both IPv4 and IPv6
+     address fields: nw_dst, nw_src, ipv6_dst and ipv6_src.
    - Userspace datapath:
      * The default zone limit, if set, is now inherited by any zone
        that does not have a specific value defined, rather than being
diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index cf4f50160b8..3df64efb9ac 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -79,8 +79,8 @@ COVERAGE_DEFINE(ofproto_update_port);
 
 /* Default fields to use for prefix tries in each flow table, unless something
  * else is configured. */
-const enum mf_field_id default_prefix_fields[2] =
-    { MFF_IPV4_DST, MFF_IPV4_SRC };
+const enum mf_field_id default_prefix_fields[4] =
+    { MFF_IPV4_DST, MFF_IPV4_SRC, MFF_IPV6_DST, MFF_IPV6_SRC };
 
 /* oftable. */
 static void oftable_init(struct oftable *);
diff --git a/ofproto/ofproto.h b/ofproto/ofproto.h
index 642a9d001f9..3f85509a1ad 100644
--- a/ofproto/ofproto.h
+++ b/ofproto/ofproto.h
@@ -562,7 +562,7 @@ struct ofproto_table_settings {
     enum mf_field_id prefix_fields[CLS_MAX_TRIES];
 };
 
-extern const enum mf_field_id default_prefix_fields[2];
+extern const enum mf_field_id default_prefix_fields[4];
 BUILD_ASSERT_DECL(ARRAY_SIZE(default_prefix_fields) <= CLS_MAX_TRIES);
 
 int ofproto_get_n_tables(const struct ofproto *);
diff --git a/tests/classifier.at b/tests/classifier.at
index 05e82ea9688..b7310f15235 100644
--- a/tests/classifier.at
+++ b/tests/classifier.at
@@ -217,6 +217,71 @@ Datapath actions: 3
 OVS_VSWITCHD_STOP(["/'prefixes' with incompatible field: ipv6_label/d"])
 AT_CLEANUP
 
+AT_SETUP([flow classifier - prefix lookup defaults])
+OVS_VSWITCHD_START
+add_of_ports br0 1 2 3
+AT_DATA([flows.txt], [dnl
+table=0 in_port=1 priority=16,tcp,nw_src=10.2.0.0/16,nw_dst=10.1.0.0/255.255.0.0,action=output(3)
+table=0 in_port=1 priority=33,tcp,nw_src=10.2.2.14,nw_dst=10.1.2.15,tp_dst=80,action=drop
+table=0 in_port=1 priority=33,tcp,nw_src=10.2.2.14,nw_dst=10.1.2.15,tp_dst=8080,action=output(2)
+table=0 in_port=1 priority=16,tcp,nw_src=192.168.0.0/16,nw_dst=192.168.0.0/255.255.0.0,action=output(3)
+table=0 in_port=1 priority=0,ip,action=drop
+table=0 in_port=1 priority=16,tcp6,ipv6_src=aaaa:bbbb:c:d:e:f::/96,ipv6_dst=aaaa:bbbb:c:d:a:f:0000:0000/96,action=output(3)
+table=0 in_port=1 priority=33,tcp6,ipv6_src=aaaa:bbbb:c:d:e:f:1:2,ipv6_dst=aaaa:bbbb:c:d:a:f:1:2,tp_dst=80,action=drop
+table=0 in_port=1 priority=33,tcp6,ipv6_src=aaaa:bbbb:c:d:e:f:1:2,ipv6_dst=aaaa:bbbb:c:d:a:f:1:2,tp_dst=8080,action=output(2)
+table=0 in_port=1 priority=16,tcp6,ipv6_src=cccc:dddd:a:b:c:d::/96,ipv6_dst=cccc:dddd:a:b:c:d::/96,action=output(3)
+table=0 in_port=1 priority=0,ip6,action=drop
+])
+AT_CHECK([ovs-ofctl add-flows br0 flows.txt])
+
+dnl nw_dst and nw_src should be on by default.
+AT_CHECK([ovs-appctl ofproto/trace br0 \
+  'in_port=1,dl_src=50:54:00:00:00:05,dl_dst=50:54:00:00:00:07,dl_type=0x0800,
+   nw_src=192.168.0.1,nw_dst=192.168.0.2,nw_proto=6,nw_tos=0,nw_ttl=128,
+   tp_src=8,tp_dst=80'], [0], [stdout])
+AT_CHECK([tail -2 stdout], [0], [dnl
+Megaflow: recirc_id=0,eth,tcp,in_port=1,nw_src=192.168.0.0/16,nw_dst=192.168.0.0/16,nw_frag=no
+Datapath actions: 3
+])
+
+dnl ipv6_dst and ipv6_src should also be on by default.
+AT_CHECK([ovs-appctl ofproto/trace br0 \
+  'in_port=1,dl_src=50:54:00:00:00:05,dl_dst=50:54:00:00:00:07,dl_type=0x86dd,
+   ipv6_src=cccc:dddd:a:b:c:d:7:8,ipv6_dst=cccc:dddd:a:b:c:d:7:9,
+   nw_proto=6,nw_tos=0,nw_ttl=128,
+   tp_src=8,tp_dst=80'], [0], [stdout])
+AT_CHECK([tail -2 stdout], [0], [dnl
+Megaflow: recirc_id=0,eth,tcp6,in_port=1,ipv6_src=cccc:dddd:a:b:c:d::/96,ipv6_dst=cccc:dddd:a:b:c:d::/96,nw_frag=no
+Datapath actions: 3
+])
+
+dnl Turn optimizations off and check that we fall back to exact match.
+AT_CHECK([ovs-vsctl set Bridge br0 flow_tables:0=@N1 -- \
+            --id=@N1 create Flow_Table name=t0], [0], [ignore])
+AT_CHECK([ovs-vsctl set Flow_Table t0 prefixes=none])
+
+AT_CHECK([ovs-appctl ofproto/trace br0 \
+  'in_port=1,dl_src=50:54:00:00:00:05,dl_dst=50:54:00:00:00:07,dl_type=0x0800,
+   nw_src=192.168.0.1,nw_dst=192.168.0.2,nw_proto=6,nw_tos=0,nw_ttl=128,
+   tp_src=8,tp_dst=80'], [0], [stdout])
+AT_CHECK([tail -2 stdout], [0], [dnl
+Megaflow: recirc_id=0,eth,tcp,in_port=1,nw_src=192.168.0.1,nw_dst=192.168.0.2,nw_frag=no
+Datapath actions: 3
+])
+
+AT_CHECK([ovs-appctl ofproto/trace br0 \
+  'in_port=1,dl_src=50:54:00:00:00:05,dl_dst=50:54:00:00:00:07,dl_type=0x86dd,
+   ipv6_src=cccc:dddd:a:b:c:d:7:8,ipv6_dst=cccc:dddd:a:b:c:d:7:9,
+   nw_proto=6,nw_tos=0,nw_ttl=128,
+   tp_src=8,tp_dst=80'], [0], [stdout])
+AT_CHECK([tail -2 stdout], [0], [dnl
+Megaflow: recirc_id=0,eth,tcp6,in_port=1,ipv6_src=cccc:dddd:a:b:c:d:7:8,ipv6_dst=cccc:dddd:a:b:c:d:7:9,nw_frag=no
+Datapath actions: 3
+])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP
+
 AT_SETUP([flow classifier - ipv6 ND dependency])
 OVS_VSWITCHD_START
 add_of_ports br0 1 2