diff --git a/releasenotes/notes/account-generator-accepts-positive-numbers-only-33a366a297494ef7.yaml b/releasenotes/notes/account-generator-accepts-positive-numbers-only-33a366a297494ef7.yaml
new file mode 100644
index 0000000..dfee1db
--- /dev/null
+++ b/releasenotes/notes/account-generator-accepts-positive-numbers-only-33a366a297494ef7.yaml
@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+   Concurrency parameter for account-generator command was accepting
+   negative values and zero. The concurrency parameter now accepts only
+   positive numbers. When a negative value or zero is passed to the
+   program then the program ends and help is displayed.
diff --git a/tempest/cmd/account_generator.py b/tempest/cmd/account_generator.py
index b230615..ff552a1 100755
--- a/tempest/cmd/account_generator.py
+++ b/tempest/cmd/account_generator.py
@@ -97,6 +97,7 @@
 [OPTIONS] <accounts_file.yaml> -h``.
 """
 
+import argparse
 import os
 import traceback
 
@@ -199,6 +200,14 @@
     LOG.info('%s generated successfully!', account_file)
 
 
+def positive_int(number):
+    number = int(number)
+    if number <= 0:
+        raise argparse.ArgumentTypeError("Concurrency value should be a "
+                                         "positive number")
+    return number
+
+
 def _parser_add_args(parser):
     parser.add_argument('-c', '--config-file',
                         metavar='/etc/tempest.conf',
@@ -228,7 +237,7 @@
                         help='Resources tag')
     parser.add_argument('-r', '--concurrency',
                         default=1,
-                        type=int,
+                        type=positive_int,
                         required=False,
                         dest='concurrency',
                         help='Concurrency count')
diff --git a/tempest/scenario/test_network_basic_ops.py b/tempest/scenario/test_network_basic_ops.py
index d8584ec..f466729 100644
--- a/tempest/scenario/test_network_basic_ops.py
+++ b/tempest/scenario/test_network_basic_ops.py
@@ -297,9 +297,19 @@
         ip_mask = CONF.network.project_network_mask_bits
         # check if the address is not already in use, if not, set it
         if ' ' + ip_address + '/' + str(ip_mask) not in ip_output:
-            ssh_client.exec_command("sudo ip addr add %s/%s dev %s" % (
-                                    ip_address, ip_mask, new_nic))
-            ssh_client.exec_command("sudo ip link set %s up" % new_nic)
+            try:
+                ssh_client.exec_command("sudo ip addr add %s/%s dev %s" % (
+                                        ip_address, ip_mask, new_nic))
+                ssh_client.exec_command("sudo ip link set %s up" % new_nic)
+            except exceptions.SSHExecCommandFailed as exc:
+                if 'RTNETLINK answers: File exists' in str(exc):
+                    LOG.debug(
+                        'IP address %(ip_address)s is already set in device '
+                        '%(device)s\nPrevious "ip a" output: %(ip_output)s',
+                        {'ip_address': ip_address, 'device': new_nic,
+                         'ip_output': ip_output})
+                else:
+                    raise exc
 
     def _get_server_nics(self, ssh_client):
         reg = re.compile(r'(?P<num>\d+): (?P<nic_name>\w+)[@]?.*:')
diff --git a/tempest/tests/cmd/test_account_generator.py b/tempest/tests/cmd/test_account_generator.py
index d15cd26..7d764be 100644
--- a/tempest/tests/cmd/test_account_generator.py
+++ b/tempest/tests/cmd/test_account_generator.py
@@ -337,3 +337,24 @@
     def setUp(self):
         self.mock_domains()
         super(TestDumpAccountsV3, self).setUp()
+
+
+class TestAccountGeneratorCliCheck(base.TestCase):
+
+    def setUp(self):
+        super(TestAccountGeneratorCliCheck, self).setUp()
+        self.account_generator = account_generator.TempestAccountGenerator(
+            app=mock.Mock(), app_args=mock.Mock())
+        self.parser = self.account_generator.get_parser("generator")
+
+    def test_account_generator_zero_concurrency(self):
+        error = self.assertRaises(
+            SystemExit, lambda: self.parser.parse_args(
+                ['-r', '0', 'accounts_file.yaml']))
+        self.assertTrue(error.code != 0)
+
+    def test_account_generator_negative_concurrency(self):
+        error = self.assertRaises(
+            SystemExit, lambda: self.parser.parse_args(
+                ['-r', '-1', 'accounts_file.yaml']))
+        self.assertTrue(error.code != 0)