def verifyArp(self, ipType='ipv4', deviceGroupName=None , silentMode=True):
        """
        Description
            Verify for ARP resolvement on every enabled Device Group including inner Device Groups.
            If device group name is specified , verify ARP on specified device group
            How it works:
               Each device group has a list of $sessionStatus: up, down or notStarted.
               If the deviceGroup has sessionStatus as "up", then ARP will be verified.
               It also has a list of $resolvedGatewayMac: MacAddress or removePacket[Unresolved]
               These two $sessionStatus and $resolvedGatewayMac lists are aligned.
               If lindex 0 on $sessionSatus is up, then $resolvedGatewayMac on index 0 expects
               to have a mac address.  Not removePacket[Unresolved].
               If not, then arp is not resolved.

        Requires
           self.deviceGroupProtocolStacksNgpf() 
           self.verifyNgpfProtocolStarted()

        Parameter
            ipType: <str>: ipv4 or ipv6
            deviceGroupName: <str>: Name of the device group to send arp request
            silentMode: <bool>: True to show less display on the terminal. False for debugging purposes.
        """
        self.ixnObj.logInfo('Verify ARP: %s' % ipType)
        unresolvedArpList = []
        startFlag = 0
        queryData = {'from': '/',
                    'nodes': [{'node': 'topology',    'properties': [], 'where': []},
                              {'node': 'deviceGroup', 'properties': [], 'where': []}
                    ]}
        queryResponse = self.ixnObj.query(data=queryData, silentMode=False)
        for topology in queryResponse.json()['result'][0]['topology']:
            for deviceGroup in topology['deviceGroup']:
                deviceGroupObj = deviceGroup['href']

                response = self.ixnObj.get(self.ixnObj.httpHeader+deviceGroupObj, silentMode=silentMode)
                deviceName = response.json()['name']
                if deviceGroupName:
                    if deviceName == deviceGroupName:
                        pass
                    else:
                        continue
                # Verify if the Device Group is enabled. If not, don't go further.
                enabledMultivalue = response.json()['enabled']
                response = self.getMultivalueValues(enabledMultivalue, silentMode=silentMode)
                if response[0] == 'false':
                    continue

                timeout = 30
                for counter in range(1,timeout+1):
                    response = self.ixnObj.get(self.ixnObj.httpHeader+deviceGroupObj, silentMode=silentMode)
                    deviceGroupStatus = response.json()['status']
                    if deviceGroupStatus == 'notStarted':
                        raise IxNetRestApiException('\nDevice Group is not started: {0}.'.format(deviceGroupObj))

                    if counter < timeout and deviceGroupStatus == 'starting':
                        self.ixnObj.logInfo('\tWait %d/%d' % (counter, timeout), timestamp=False)
                        time.sleep(1)
                        continue
                    if counter < timeout and deviceGroupStatus in ['started', 'mixed']:
                        break
                    if counter == timeout and deviceGroupStatus not in ['started', 'mixed']:
                        raise IxNetRestApiException('\nDevice Group failed to come up: {0}.'.format(deviceGroupObj))

                if deviceGroupStatus in ['started', 'mixed']:
                    startFlag = 1
                    arpResult = self.deviceGroupProtocolStackNgpf(deviceGroupObj, ipType, silentMode=silentMode)
                    if arpResult != 0:
                        unresolvedArpList = unresolvedArpList + arpResult

                    response = self.ixnObj.get(self.ixnObj.httpHeader+deviceGroupObj+'/deviceGroup', silentMode=silentMode)
                    if response.status_code == 200 and response.json() != []:
                        innerDeviceGroupObj = response.json()[0]['links'][0]['href']
                        self.ixnObj.logInfo('%s' % self.ixnObj.httpHeader+innerDeviceGroupObj, timestamp=False)
                        response = self.ixnObj.get(self.ixnObj.httpHeader+innerDeviceGroupObj, silentMode=silentMode)
                        deviceGroupStatus1 = response.json()['status']
                        self.ixnObj.logInfo('\tdeviceGroup Status: %s' % deviceGroupStatus1, timestamp=False)

                        if deviceGroupStatus == 'started':
                            arpResult = self.deviceGroupProtocolStackNgpf(innerDeviceGroupObj, ipType, silentMode=silentMode)
                            if arpResult != 0:
                                unresolvedArpList = unresolvedArpList + arpResult

        if unresolvedArpList == [] and startFlag == 0:
            # Device group status is not started.
            raise IxNetRestApiException("\nError: Device Group is not started. It must've went down. Can't verify arp.")

        if unresolvedArpList != [] and startFlag == 1:
            # Device group status is started and there are arp unresolved.
            print()
            raise IxNetRestApiException('\nError: Unresolved ARP: {0}'.format(unresolvedArpList))