@@ 4,7 4,7 @@ from sqlalchemy.sql.sqltypes import Enum
 BoardStatusEnum = Enum("open", "restricted", "locked", "archived", name="board_status")
 
 
-IdentTypeEnum = Enum("none", "ident", "ident_admin", name="ident_type")
+IdentTypeEnum = Enum("none", "ident", "ident_v6", "ident_admin", name="ident_type")
 
 
 TopicStatusEnum = Enum("open", "locked", "archived", "expired", name="topic_status")

@@ 1,4 1,5 @@
 import datetime
+import ipaddress
 
 from sqlalchemy.sql import func
 


@@ 90,10 91,21 @@ class PostCreateService(object):
         ident_type = "none"
         if board.settings["use_ident"]:
             ident_type = "ident"
+            ident_addr = ip_address
+
+            # Since it's common for IPv6 setup to delegate a /64 from ISP to a home
+            # network, it makes more sense here to always generate ident based on
+            # /64 network instead of individual address.
+            if ipaddress.ip_address(ip_address).version == 6:
+                ident_type = "ident_v6"
+                ident_addr = str(
+                    ipaddress.ip_network("%s/64" % (ip_address,), strict=False)
+                )
+
             ident = self.identity_svc.identity_with_tz_for(
                 self.setting_query_svc.value_from_key("app.time_zone"),
                 board=topic.board.slug,
-                ip_address=ip_address,
+                ip_address=ident_addr,
             )
 
         post = Post(

@@ 52,6 52,23 @@ class TestPostCreateService(ModelSessionMixin, unittest.TestCase):
         self.assertEqual(topic_meta.post_count, 1)
         self.assertIsNotNone(topic_meta.bumped_at)
 
+    def test_create_ipv6(self):
+        from ..models import Board, Topic, TopicMeta
+
+        board = self._make(Board(slug="foo", title="Foo"))
+        topic = self._make(Topic(board=board, title="Hello", status="open"))
+        self._make(TopicMeta(topic=topic, post_count=0))
+        self.dbsession.commit()
+        post_create_svc = self._make_one()
+        post1 = post_create_svc.create(topic.id, "Hello!", True, "fe80:c9cd::1")
+        self.assertEqual(post1.ip_address, "fe80:c9cd::1")
+        self.assertEqual(post1.ident, "foo,fe80:c9cd::/64")
+        self.assertEqual(post1.ident_type, "ident_v6")
+        post2 = post_create_svc.create(topic.id, "Hello!", True, "fe80:c9cd::96f0:1111")
+        self.assertEqual(post2.ip_address, "fe80:c9cd::96f0:1111")
+        self.assertEqual(post2.ident, "foo,fe80:c9cd::/64")
+        self.assertEqual(post2.ident_type, "ident_v6")
+
     def test_create_without_bumped(self):
         from ..models import Board, Topic, TopicMeta
 

@@ 0,0 1,54 @@
+"""add ident_v6 ident type
+
+Revision ID: 5d4ef3966456
+Revises: 06000cefb0bb
+Create Date: 2020-03-30 19:29:21.471805
+"""
+from alembic import op
+from sqlalchemy.dialects.postgresql import ENUM
+import sqlalchemy as sa
+
+
+revision = "5d4ef3966456"
+down_revision = "06000cefb0bb"
+
+
+def alter_enum(enum_name, enum_value, fields=None):
+    op.execute("ALTER TYPE %s RENAME TO %s_1" % (enum_name, enum_name))
+
+    new_enum = sa.Enum(*enum_value, name=enum_name)
+    new_enum.create(op.get_bind(), checkfirst=True)
+    if fields:
+        for table, column in fields:
+            op.alter_column(
+                table,
+                column,
+                type_=new_enum,
+                postgresql_using="%s::text::%s" % (column, enum_name),
+            )
+
+    ENUM(name="%s_1" % enum_name).drop(op.get_bind(), checkfirst=True)
+
+
+def upgrade():
+    alter_enum(
+        "ident_type",
+        ("none", "ident", "ident_v6", "ident_admin"),
+        (
+            ("user", "ident_type"),
+            ("post", "ident_type"),
+            ("post_history", "ident_type"),
+        ),
+    )
+
+
+def downgrade():
+    alter_enum(
+        "ident_type",
+        ("none", "ident", "ident_admin"),
+        (
+            ("user", "ident_type"),
+            ("post", "ident_type"),
+            ("post_history", "ident_type"),
+        ),
+    )