diff --git a/manager/cli.py b/manager/cli.py
index 75a07e1..446b919 100644
--- a/manager/cli.py
+++ b/manager/cli.py
@@ -87,7 +87,7 @@ def create_parser() -> argparse.ArgumentParser:
         'vlan',
         help='Configure the ports to be in VLAN groups',
     )
-    vlan_parser_group = vlan_parser.add_mutually_exclusive_group()
+    vlan_parser_group = vlan_parser.add_mutually_exclusive_group(required=True)
     vlan_parser_group.add_argument(
         '-g',
         '--group',
@@ -97,8 +97,11 @@ def create_parser() -> argparse.ArgumentParser:
         choices=[1, 2, 3, 4, 5],
         required=False,
         help='''Define the VLAN member groups using port number,
-        i.e. --group 1 2 --group 3 4 puts makes Group A have
-        ports 1 and 2, and Group B have ports 3 and 4'''
+        i.e. --group 1 2 --group 3 4 makes Group A have
+        ports 1 and 2 and Group B have ports 3 and 4. All unmentioned
+        ports are assigned to default group. If a group has only 1 port,
+        the port gets isolated. In this example, port 5 would
+        not be allowed to communicate with any other port.'''
     )
     vlan_parser_group.add_argument(
         '-r',
diff --git a/manager/data_manager/vlan.py b/manager/data_manager/vlan.py
index fcd52bc..3a5a353 100644
--- a/manager/data_manager/vlan.py
+++ b/manager/data_manager/vlan.py
@@ -19,7 +19,7 @@ class VlanConfig:
             'sys_default': 0xFF,
             'data': 0,
             'choice_mapping': {
-                1: 0b00000010,
+                1: 0b00000100,
             }
         },
         2: {
@@ -31,7 +31,7 @@ class VlanConfig:
             'sys_default': 0xFF,
             'data': 0,
             'choice_mapping': {
-                2: 0b00000100,
+                2: 0b00001000,
             }
         },
         3: {
@@ -43,7 +43,7 @@ class VlanConfig:
             'sys_default': 0xFF,
             'data': 0,
             'choice_mapping': {
-                3: 0b00001000,
+                3: 0b00010000,
             }
         },
         4: {

diff --git a/tests/vlan/test_set_groups.py b/tests/vlan/test_set_groups.py
index 6a6a89c..ac1bb76 100644
--- a/tests/vlan/test_set_groups.py
+++ b/tests/vlan/test_set_groups.py
@@ -8,7 +8,7 @@ from typing import (
 )
 
 
-class TestSetRxMode:
+class TestSetGroups:
     package: List[str] = ['botblox']
     base_args: List[str] = [
         '--device',
@@ -45,7 +45,7 @@ class TestSetRxMode:
         cli_status_code: int = subprocess.call(command)
         assert cli_status_code > 0, 'The command did not exit with an error code'
 
-    def test_single_rx_port(
+    def test_2x2_groups_1_isolated(
         self,
         parser: ArgumentParser,
     ) -> None:
@@ -61,5 +61,5 @@ class TestSetRxMode:
         data = self._get_data_from_cli_args(parser=parser, args=args)
         self._assert_data_is_correct_type(data=data)
 
-        expected_result = [[23, 16, 6, 6], [23, 17, 72, 0], [23, 18, 72, 255]]
+        expected_result = [[23, 16, 12, 12], [23, 17, 80, 0], [23, 18, 80, 255]]
         assert data == expected_result

Switch not switching after setting up port-based VLAN
I've set up port-based VLAN using the following command:

    python3.8 -m manager -D /dev/ttyACM0 vlan --group 1 2 --group 3 4 5

After this command, cables connected to ports 1 and 2 are not able to communicate. When I reset the vlan config, the communication is without problems. I also tried other ports, but it seems that setting any vlan config, all ports that are part of any vlan group are not able to communicate. Their LEDs blink, but no data pass through the switch.

I'll try to investigate this more in depth.
tests/vlan/test_set_groups.py::TestSetGroups::test_2x2_groups_1_isolated