diff --git a/tests/tacacs/test_accounting.py b/tests/tacacs/test_accounting.py
index 4c06554a6f5..81b77df6067 100644
--- a/tests/tacacs/test_accounting.py
+++ b/tests/tacacs/test_accounting.py
@@ -10,7 +10,8 @@
         remove_all_tacacs_server
 from .utils import stop_tacacs_server, start_tacacs_server, \
         check_server_received, per_command_accounting_skip_versions, \
-        change_and_wait_aaa_config_update, ensure_tacacs_server_running_after_ut  # noqa: F401
+        change_and_wait_aaa_config_update, get_auditd_config_reload_timestamp, \
+        ensure_tacacs_server_running_after_ut  # noqa: F401
 from tests.common.errors import RunAnsibleModuleFail
 from tests.common.helpers.assertions import pytest_assert
 from tests.common.utilities import skip_release
@@ -219,11 +220,19 @@ def test_accounting_tacacs_only_some_tacacs_server_down(
     invalid_tacacs_server_ip = "127.0.0.1"
     duthost = duthosts[enum_rand_one_per_hwsku_hostname]
     tacacs_server_ip = ptfhost.mgmt_ip
+
+    # when tacacs config change multiple time in short time
+    # auditd service may been request reload during reloading
+    # when this happen, auditd will ignore request and only reload once
+    last_timestamp = get_auditd_config_reload_timestamp(duthost)
+
     duthost.shell("sudo config tacacs timeout 1")
     remove_all_tacacs_server(duthost)
     duthost.shell("sudo config tacacs add %s" % invalid_tacacs_server_ip)
     duthost.shell("sudo config tacacs add %s" % tacacs_server_ip)
-    change_and_wait_aaa_config_update(duthost, "sudo config aaa accounting tacacs+")
+    change_and_wait_aaa_config_update(duthost,
+                                      "sudo config aaa accounting tacacs+",
+                                      last_timestamp)
 
     cleanup_tacacs_log(ptfhost, rw_user_client)
 
diff --git a/tests/tacacs/utils.py b/tests/tacacs/utils.py
index b5532613bd1..d18e631ede0 100644
--- a/tests/tacacs/utils.py
+++ b/tests/tacacs/utils.py
@@ -72,6 +72,12 @@ def setup_local_user(duthost, tacacs_creds):
 def setup_tacacs_client(duthost, tacacs_creds, tacacs_server_ip):
     """setup tacacs client"""
 
+    # UT should failed when set reachable TACACS server with this setup_tacacs_client
+    ping_result = duthost.shell("ping {} -c 1 -W 3".format(tacacs_server_ip))['stdout']
+    logger.info("TACACS server ping result: {}".format(ping_result))
+    if "100% packet loss" in ping_result:
+        pytest_assert(False, "TACACS server not reachable: {}".format(ping_result))
+
     # configure tacacs client
     default_tacacs_servers = []
     duthost.shell("sudo config tacacs passkey %s" % tacacs_creds[duthost.hostname]['tacacs_passkey'])
@@ -318,8 +324,10 @@ def get_auditd_config_reload_timestamp(duthost):
     return res["stdout_lines"][-1]
 
 
-def change_and_wait_aaa_config_update(duthost, command, timeout=10):
-    last_timestamp = get_auditd_config_reload_timestamp(duthost)
+def change_and_wait_aaa_config_update(duthost, command, last_timestamp=None, timeout=10):
+    if not last_timestamp:
+        last_timestamp = get_auditd_config_reload_timestamp(duthost)
+
     duthost.shell(command)
 
     # After AAA config update, hostcfgd will modify config file and notify auditd reload config