---
title: "CT Cloud Voice - NSlookup"
slug: "ct-cloud-voice-nslookup"
tags: ["calltower", "public"]
updated: 2026-09-18T16:33:34Z
published: 2026-09-18T16:33:34Z
canonical: "learn.calltower.com/ct-cloud-voice-nslookup"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://learn.calltower.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CT Cloud Voice - NSlookup

## Goal

This article is to show you how to use the NSlookup tool using Command Prompt (CND)

### First Step

Start by searching for CMD in your windows search bar next to the windows tab on your PC and select Command Prompt.

after you have Command Prompt open start by typing the following you will need to go line by line.

**nslookup**

**> set type=all**

**> server 8.8.8.8**

**Unrecognized command: server 8.8.8.8**

**> server 8.8.8.8**

**Default Server: dns.google**

**Address: 8.8.8.8**

**_sip._udp.(Domain for Trunk I.E trunknumber.siptrunking.appiaservices.com) not the period after SIP. and udp. and hit enter.**

Below is an example of a failed look up

![failedNSlookup.PNG](https://cdn.us.document360.io/4662144b-ab1f-4796-8b7b-e9f9c609894f/Images/Documentation/failedNSlookup.PNG?sv=2026-02-06&spr=https&st=2026-11-05T00%3A08%3A24Z&se=2026-11-05T01%3A08%3A24Z&sr=c&sp=r&sig=yUgiEmEdqXffKWEry%2BuV4xS2AENWfWwnpqCaRQquQBE%3D)

***** dns.google can't find _sip._udp.7005476001.siptrunking.appiaservices.com: Non-existent domain**

Example of a successful lookup

![NSlookup.PNG](https://cdn.us.document360.io/4662144b-ab1f-4796-8b7b-e9f9c609894f/Images/Documentation/NSlookup.PNG?sv=2026-02-06&spr=https&st=2026-11-05T00%3A08%3A24Z&se=2026-11-05T01%3A08%3A24Z&sr=c&sp=r&sig=yUgiEmEdqXffKWEry%2BuV4xS2AENWfWwnpqCaRQquQBE%3D)

A communication line or link that carries multiple signals simultaneously to provide network connectivity.

Session Initiation Protocol, is the technology that starts, manages, and ends internet-based phone calls and video meetings between people and devices.