diff --git a/fake_switches/cisco/command_processor/config_interface.py b/fake_switches/cisco/command_processor/config_interface.py
index 29195051..99af3a75 100644
--- a/fake_switches/cisco/command_processor/config_interface.py
+++ b/fake_switches/cisco/command_processor/config_interface.py
@@ -18,6 +18,8 @@
 from fake_switches.command_processing.base_command_processor import BaseCommandProcessor
 from fake_switches.switch_configuration import VlanPort
 
+from fake_switches.utils.ip_validator import InvalidIpError, IncompleteIpError, valid_ip_v4
+
 
 class ConfigInterfaceCommandProcessor(BaseCommandProcessor):
     def init(self, switch_configuration, terminal_controller, logger, piping_processor, *args):
@@ -139,9 +141,19 @@ def do_ip(self, *args):
                 self.write_line("% Invalid input detected at '^' marker.")
                 self.write_line("")
             else:
-                ip_address = IPAddress(args[1])
-                if ip_address not in self.port.ip_helpers:
-                    self.port.ip_helpers.append(ip_address)
+                try:
+                    ip_address = _parse_ip(args[1], 4)
+                    if ip_address is None:
+                        raise InvalidIpError
+                    if ip_address not in self.port.ip_helpers:
+                        self.port.ip_helpers.append(ip_address)
+                except InvalidIpError:
+                    self.write_line(" ^")
+                    self.write_line("% Invalid input detected at '^' marker.")
+                    self.write_line("")
+                except IncompleteIpError:
+                    self.write_line("% Incomplete command.")
+                    self.write_line("")
 
     def do_no_ip(self, *args):
         if "address".startswith(args[0]):
@@ -333,7 +345,11 @@ def parse_vlan_list(param):
     return vlans
 
 
-def _parse_ip(ip):
+def _parse_ip(ip, strict_format=None):
+    if strict_format == 4 and not valid_ip_v4(ip):
+        return None
+    elif strict_format and strict_format != 4:
+        raise NotImplementedError("Ip format {} validation not supported.".format(strict_format))
     try:
         return IPAddress(ip)
     except:
diff --git a/fake_switches/utils/__init__.py b/fake_switches/utils/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/fake_switches/utils/ip_validator.py b/fake_switches/utils/ip_validator.py
new file mode 100644
index 00000000..f42cef7d
--- /dev/null
+++ b/fake_switches/utils/ip_validator.py
@@ -0,0 +1,16 @@
+def valid_ip_v4(address):
+    parts = address.split(".")
+    for item in parts:
+        if not item.isdigit() or not 0 <= int(item) <= 255:
+            raise InvalidIpError
+    if len(parts) != 4:
+        raise IncompleteIpError
+    return True
+
+
+class InvalidIpError(Exception):
+    pass
+
+
+class IncompleteIpError(Exception):
+    pass
diff --git a/tests/cisco/test_cisco_switch_protocol.py b/tests/cisco/test_cisco_switch_protocol.py
index d7b859a2..53b87f24 100644
--- a/tests/cisco/test_cisco_switch_protocol.py
+++ b/tests/cisco/test_cisco_switch_protocol.py
@@ -1240,8 +1240,23 @@ def test_ip_helper(self, t):
         t.write("ip helper-address")
         t.readln("% Incomplete command.")
         t.readln("")
+
+        t.read("my_switch(config-if)#")
+        t.write("ip helper-address 1.1.1")
+        t.readln("% Incomplete command.")
+        t.readln("")
         t.read("my_switch(config-if)#")
+        t.write("ip helper-address 1.a.1")
+        t.readln(" ^")
+        t.readln("% Invalid input detected at '^' marker.")  # not incomplete
+        t.readln("")
+        t.read("my_switch(config-if)#")
+        t.write("ip helper-address invalid.ip")
+        t.readln(" ^")
+        t.readln("% Invalid input detected at '^' marker.")
+        t.readln("")
 
+        t.read("my_switch(config-if)#")
         t.write("ip helper-address 10.10.0.1 EXTRA INFO")
         t.readln(" ^")
         t.readln("% Invalid input detected at '^' marker.")