diff --git a/inv/models/macblacklist.py b/inv/models/macblacklist.py
new file mode 100644
index 0000000000000000000000000000000000000000..958d2b5da5e67ff3e0bc73d171f786e02df9a7b8
--- /dev/null
+++ b/inv/models/macblacklist.py
@@ -0,0 +1,132 @@
+# ----------------------------------------------------------------------
+# MACBlacklist model
+# ----------------------------------------------------------------------
+# Copyright (C) 2007-2020 The NOC Project
+# See LICENSE for details
+# ----------------------------------------------------------------------
+
+# Python modules
+import operator
+from threading import Lock
+from collections import namedtuple
+from typing import List
+
+# Third-party modules
+from mongoengine.document import Document, EmbeddedDocument
+from mongoengine.fields import (
+    StringField,
+    BooleanField,
+    UUIDField,
+    ListField,
+    EmbeddedDocumentField,
+)
+import cachetools
+
+# NOC modules
+from noc.inv.models.vendor import Vendor
+from noc.inv.models.platform import Platform
+from noc.core.mongo.fields import PlainReferenceField
+from noc.core.prettyjson import to_json
+from noc.core.mac import MAC
+
+_list_lock = Lock()
+ListItem = namedtuple("ListItem", ["from_mac", "to_mac", "is_duplicated"])
+
+
+class MACBlacklistAffected(EmbeddedDocument):
+    vendor = PlainReferenceField(Vendor)
+    platform = PlainReferenceField(Platform)
+
+    def __str__(self):
+        if self.platform:
+            return "%s:%s" % (self.vendor.name, self.platform.name)
+        return self.vendor.name
+
+    def to_json(self):
+        r = {"vendor__code": self.vendor.code}
+        if self.platform:
+            r["platform__name"] = self.platform.name
+        return r
+
+
+class MACBlacklist(Document):
+    meta = {
+        "collection": "macblacklist",
+        "strict": False,
+        "auto_create_index": False,
+        "json_collection": "inv.macblacklist",
+        "json_depends_on": ["inv.vendor", "inv.platform"],
+    }
+
+    name = StringField(unique=True)
+    # Unique id
+    uuid = UUIDField(binary=True)
+    #
+    from_mac = StringField()
+    to_mac = StringField()
+    description = StringField()
+    affected = ListField(EmbeddedDocumentField(MACBlacklistAffected))
+    is_duplicated = BooleanField(default=False)
+
+    _list_cache = cachetools.TTLCache(100, ttl=60)
+
+    def __str__(self):
+        return self.name
+
+    def clean(self):
+        super().clean()
+        self.from_mac = str(MAC(self.from_mac))
+        self.to_mac = str(MAC(self.to_mac))
+        if self.from_mac > self.to_mac:
+            self.from_mac, self.to_mac = self.to_mac, self.from_mac
+
+    def to_json(self):
+        r = {
+            "name": self.name,
+            "$collection": self._meta["json_collection"],
+            "uuid": self.uuid,
+            "from_mac": self.from_mac,
+            "to_mac": self.to_mac,
+            "affected": [a.to_json() for a in self.affected],
+            "is_duplicated": self.is_duplicated,
+        }
+        if self.description:
+            r["description"] = self.description
+        return to_json(
+            r,
+            order=[
+                "name",
+                "uuid",
+                "from_mac",
+                "to_mac",
+                "description",
+                "is_duplicated",
+                "affected",
+            ],
+        )
+
+    def get_json_path(self):
+        return "%s.json" % self.name
+
+    @classmethod
+    @cachetools.cachedmethod(operator.attrgetter("_list_cache"), lock=lambda _: _list_lock)
+    def _get_blacklist(cls) -> List[ListItem]:
+        return [
+            ListItem(from_mac=MAC(d.from_mac), to_mac=MAC(d.to_mac), is_duplicated=d.is_duplicated)
+            for d in cls.objects.all()
+        ]
+
+    @classmethod
+    def is_banned_mac(cls, mac: str, is_duplicated: bool = False) -> bool:
+        """
+        Check if mac is banned for specified reason
+        :param mac:
+        :param is_duplicated:
+        :return:
+        """
+        m = MAC(mac)
+        for item in cls._get_blacklist():
+            if item.from_mac <= m <= item.to_mac:
+                if is_duplicated and item.is_duplicated:
+                    return True
+        return False
diff --git a/models.py b/models.py
index 3cbdd526f2ae1b2bb738666cce1c12b4f426411e..0e36116b5d8a95efee86bbcdf9c9c61bb9a6eec0 100644
--- a/models.py
+++ b/models.py
@@ -155,6 +155,7 @@ _MODELS = {
     "inv.InterfaceClassificationRule": "noc.inv.models.interfaceclassificationrule.InterfaceClassificationRule",
     "inv.InterfaceProfile": "noc.inv.models.interfaceprofile.InterfaceProfile",
     "inv.Link": "noc.inv.models.link.Link",
+    "inv.MACBlacklist": "noc.inv.models.macblacklist.MACBlacklist",
     "inv.MACDB": "noc.inv.models.macdb.MACDB",
     "inv.MACLog": "noc.inv.models.maclog.MACLog",
     "inv.MapSettings": "noc.inv.models.mapsettings.MapSettings",
@@ -335,6 +336,7 @@ COLLECTIONS = [
     "inv.Vendor",
     "inv.Platform",
     "inv.Firmware",
+    "inv.MACBlacklist",
     "fm.MIBAlias",
     "gis.Layer",
     "fm.OIDAlias",
diff --git a/services/discovery/jobs/base.py b/services/discovery/jobs/base.py
index 4c409c686df75ec35a455f48de3138ed0bff599d..399bed9e899405528442f058c4a73c9db1ead3b6 100644
--- a/services/discovery/jobs/base.py
+++ b/services/discovery/jobs/base.py
@@ -909,9 +909,10 @@ class TopologyDiscoveryCheck(DiscoveryCheck):
         Resolve neighbor by hostname
         """
         if hostname not in self.neighbor_hostname_cache:
-            n = DiscoveryID.objects.filter(hostname=hostname).first()
-            if n:
-                n = n.object
+            hosts = DiscoveryID.objects.filter(hostname=hostname)[:2]
+            n = None
+            if len(hosts) == 1:
+                n = hosts[0].object
             elif "." not in hostname:
                 # Sometimes, domain part is truncated.
                 # Try to resolve anyway
diff --git a/services/discovery/jobs/box/lldp.py b/services/discovery/jobs/box/lldp.py
index 16db4af12aba8d76ab68d912962bdfc975fa84aa..4f9090c9b91a7f3f9a96adc653c676453540a8cb 100644
--- a/services/discovery/jobs/box/lldp.py
+++ b/services/discovery/jobs/box/lldp.py
@@ -1,7 +1,7 @@
 # ---------------------------------------------------------------------
 # LLDP check
 # ---------------------------------------------------------------------
-# Copyright (C) 2007-2019 The NOC Project
+# Copyright (C) 2007-2020 The NOC Project
 # See LICENSE for details
 # ---------------------------------------------------------------------
 
@@ -21,6 +21,7 @@ from noc.core.lldp import (
     LLDP_PORT_SUBTYPE_LOCAL,
     LLDP_PORT_SUBTYPE_UNSPECIFIED,
 )
+from noc.inv.models.macblacklist import MACBlacklist
 
 
 class LLDPCheck(TopologyDiscoveryCheck):
@@ -47,7 +48,15 @@ class LLDPCheck(TopologyDiscoveryCheck):
         chassis_subtype = neighbor_id["remote_chassis_id_subtype"]
         chassis_id = neighbor_id["remote_chassis_id"]
         if chassis_subtype == LLDP_CHASSIS_SUBTYPE_MAC:
-            return self.get_neighbor_by_mac(chassis_id)
+            if MACBlacklist.is_banned_mac(chassis_id, is_duplicated=True):
+                self.logger.info("Banned MAC %s found. Trying to negotiate via hostname")
+                if "remote_system_name" in neighbor_id:
+                    return self.get_neighbor_by_hostname(neighbor_id["remote_system_name"])
+                else:
+                    self.logger.info("No remote hostname for %s. Giving up.")
+                    return None
+            else:
+                return self.get_neighbor_by_mac(chassis_id)
         elif chassis_subtype == LLDP_CHASSIS_SUBTYPE_NETWORK_ADDRESS:
             return self.get_neighbor_by_ip(chassis_id)
         elif chassis_subtype == LLDP_CHASSIS_SUBTYPE_LOCAL:
diff --git a/services/web/apps/inv/macblacklist/__init__.py b/services/web/apps/inv/macblacklist/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/services/web/apps/inv/macblacklist/views.py b/services/web/apps/inv/macblacklist/views.py
new file mode 100644
index 0000000000000000000000000000000000000000..7100c8ae0c74263b9ca52140b4a925b8872b63b6
--- /dev/null
+++ b/services/web/apps/inv/macblacklist/views.py
@@ -0,0 +1,21 @@
+# ----------------------------------------------------------------------
+# inv.macblacklist application
+# ----------------------------------------------------------------------
+# Copyright (C) 2007-2020 The NOC Project
+# See LICENSE for details
+# ----------------------------------------------------------------------
+
+# NOC modules
+from noc.lib.app.extdocapplication import ExtDocApplication
+from noc.inv.models.macblacklist import MACBlacklist
+from noc.core.translation import ugettext as _
+
+
+class MACBlacklistApplication(ExtDocApplication):
+    """
+    MACBlacklist application
+    """
+
+    title = "MAC Blacklist"
+    menu = [_("Setup"), _("MAC Blacklist")]
+    model = MACBlacklist
diff --git a/ui/web/inv/macblacklist/Application.js b/ui/web/inv/macblacklist/Application.js
new file mode 100644
index 0000000000000000000000000000000000000000..060a3316b31dfee3c9602862cf173c46441252a4
--- /dev/null
+++ b/ui/web/inv/macblacklist/Application.js
@@ -0,0 +1,153 @@
+//---------------------------------------------------------------------
+// inv.macblacklist application
+//---------------------------------------------------------------------
+// Copyright (C) 2007-2020 The NOC Project
+// See LICENSE for details
+//---------------------------------------------------------------------
+console.debug("Defining NOC.inv.macblacklist.Application");
+
+Ext.define("NOC.inv.macblacklist.Application", {
+    extend: "NOC.core.ModelApplication",
+    requires: [
+        "NOC.inv.macblacklist.Model",
+        "NOC.inv.vendor.LookupField",
+        "NOC.inv.platform.LookupField"
+    ],
+    model: "NOC.inv.macblacklist.Model",
+    search: true,
+    initComponent: function() {
+        var me = this;
+
+        me.jsonPanel = Ext.create("NOC.core.JSONPreview", {
+            app: me,
+            restUrl: new Ext.XTemplate('/inv/macblacklist/{id}/json/'),
+            previewName: new Ext.XTemplate('MAC Blacklist: {name}')
+        });
+
+        me.ITEM_JSON = me.registerItem(me.jsonPanel);
+
+        Ext.apply(me, {
+            columns: [
+                {
+                    text: __("Name"),
+                    dataIndex: "name",
+                    width: 150
+                },
+                {
+                    text: __("From"),
+                    dataIndex: "from_mac",
+                    width: 150
+                },
+                {
+                    text: __("To"),
+                    dataIndex: "from_mac",
+                    width: 150
+                },
+                {
+                    text: __("Duplicate"),
+                    dataIndex: "is_duplicated",
+                    width: 50,
+                    renderer: NOC.render.Bool
+                }
+            ],
+
+            fields: [
+                {
+                    name: "name",
+                    xtype: "textfield",
+                    fieldLabel: __("Name"),
+                    allowBlank: false,
+                    uiStyle: "medium"
+                },
+                {
+                    name: "uuid",
+                    xtype: "displayfield",
+                    fieldLabel: __("UUID"),
+                    allowBlank: false
+                },
+                {
+                    name: "description",
+                    xtype: "textarea",
+                    fieldLabel: __("Description"),
+                    allowBlank: true
+                },
+                {
+                    xtype: "container",
+                    layout: "hbox",
+                    defaults: {
+                        padding: 4
+                    },
+                    items: [
+                        {
+                            name: "from_mac",
+                            xtype: "textfield",
+                            fieldLabel: __("From"),
+                            uiStyle: "medium",
+                            allowBlank: false
+                        },
+                        {
+                            name: "to_mac",
+                            xtype: "textfield",
+                            fieldLabel: __("To"),
+                            uiStyle: "medium",
+                            allowBlank: false
+                        }
+                    ]
+                },
+                {
+                    xtype: "fieldset",
+                    title: __("Reason"),
+                    defaults: {
+                        padding: 4
+                    },
+                    items: [
+                        {
+                            name: "is_duplicated",
+                            xtype: "checkbox",
+                            boxLabel: __("Duplicated")
+                        }
+                    ]
+                },
+                {
+                    name: "affected",
+                    xtype: "gridfield",
+                    fieldLabel: __("Affected"),
+                    columns: [
+                        {
+                            text: __("Vendor"),
+                            dataIndex: "vendor",
+                            editor: "inv.vendor.LookupField",
+                            width: 200,
+                            renderer: NOC.render.Lookup("vendor")
+                        },
+                        {
+                            text: __("Platform"),
+                            dataIndex: "platform",
+                            editor: "inv.platform.LookupField",
+                            width: 200,
+                            renderer: NOC.render.Lookup("platform")
+                        }
+                    ]
+                }
+            ],
+            formToolbar: [
+                {
+                    text: __("JSON"),
+                    glyph: NOC.glyph.file,
+                    tooltip: __("Show JSON"),
+                    hasAccess: NOC.hasPermission("read"),
+                    scope: me,
+                    handler: me.onJSON
+                }
+            ]
+        });
+        me.callParent();
+    },
+
+    //
+    onJSON: function() {
+        var me = this;
+        me.showItem(me.ITEM_JSON);
+        me.jsonPanel.preview(me.currentRecord);
+    }
+});
\ No newline at end of file
diff --git a/ui/web/inv/macblacklist/LookupField.js b/ui/web/inv/macblacklist/LookupField.js
new file mode 100644
index 0000000000000000000000000000000000000000..0483272b002d2b0f86b3a77334f0f69eea0d3cbf
--- /dev/null
+++ b/ui/web/inv/macblacklist/LookupField.js
@@ -0,0 +1,12 @@
+//---------------------------------------------------------------------
+// NOC.inv.macblacklist.Lookup
+//---------------------------------------------------------------------
+// Copyright (C) 2007-2020 The NOC Project
+// See LICENSE for details
+//---------------------------------------------------------------------
+console.debug("Defining NOC.inv.macblacklist.LookupField");
+
+Ext.define("NOC.inv.macblacklist.LookupField", {
+    extend: "NOC.core.LookupField",
+    alias: "widget.inv.macblacklist.LookupField"
+});
\ No newline at end of file
diff --git a/ui/web/inv/macblacklist/Model.js b/ui/web/inv/macblacklist/Model.js
new file mode 100644
index 0000000000000000000000000000000000000000..c5c9053135d556fbce33845428c5f7ad78a4d087
--- /dev/null
+++ b/ui/web/inv/macblacklist/Model.js
@@ -0,0 +1,47 @@
+//---------------------------------------------------------------------
+// inv.macblacklist Model
+//---------------------------------------------------------------------
+// Copyright (C) 2007-2020 The NOC Project
+// See LICENSE for details
+//---------------------------------------------------------------------
+console.debug("Defining NOC.inv.macblacklist.Model");
+
+Ext.define("NOC.inv.macblacklist.Model", {
+    extend: "Ext.data.Model",
+    rest_url: "/inv/macblacklist/",
+
+    fields: [
+        {
+            name: "id",
+            type: "string"
+        },
+        {
+            name: "name",
+            type: "string"
+        },
+        {
+            name: "uuid",
+            type: "string"
+        },
+        {
+            name: "from_mac",
+            type: "string"
+        },
+        {
+            name: "to_mac",
+            type: "string"
+        },
+        {
+            name: "description",
+            type: "string"
+        },
+        {
+            name: "affected",
+            type: "auto"
+        },
+        {
+            name: "is_duplicated",
+            type: "boolean"
+        }
+    ]
+});
\ No newline at end of file