## Troubleshooting API Connectivity with Postman (Mutual TLS)

Often, connectivity problems result in a general **"SSL handshake error"**, which can be caused by various errors related to a mutual TLS Authentication failure. This guide describes how to test and verify connectivity using **Postman** — an API client that allows you to easily create and save simple and complex HTTP/s requests and read their responses.

### Common Causes of Connectivity Issues

Connectivity issues related to Mutual TLS Authentication failures may include:

* The certificate is not configured correctly in the customer integration engine
* An incorrect URL is being used
* The customer IP address is not on the allow list
* Cipher Suites are not supported by Verato
* SNI (Server Name Indication) is not supported by the customer integration engine


### What You Will Need

If you contact customer support to help you troubleshoot API connectivity issues, we request the following information to help us troubleshoot the problem and find a solution as quickly as possible:

1. The client IP address to be added to the allow list by Verato
2. The client email address with whom the credentials (Verato username/account) should be shared.
3. **Optional:** Does the client need Verato IPs to be added to the allow list on their end?


Once this information is shared with the Verato support agent, we create an environment and share credentials with the client for them to connect with Verato.

In addition, to connect successfully with Verato, you will need the following information, which will be sent in encrypted emails by Verato:

* The API username for their environment
* The URL for the environment
* The API password for their environment
* The API certificate to successfully authenticate via Mutual TLS
* The password for the API certificate shared


### Configuring and Testing Connectivity with Postman

Once you have gathered all of the necessary information and credentials outlined in the previous section, follow these steps to connect via Postman.

1. **Open Postman.** From the main menu, select **File** > **New**.
2. Select **Request**.
3. Enter the name of the request and a collection where this request needs to be saved. (You can create a new collection or use an existing collection.)
4. After the request is created, the Postman screen will show a new `GET` method request.
5. Now, since all Verato API calls are `POST` method requests, please modify the `GET` request to `POST`.
  * Select the `GET` request drop down, and then select **POST**.
6. Enter the complete URL (emailed to you by Verato) and resource type in the following format:
  * `https://custXXXX.verato-connect.com`, where `XXXX` will be a 4-digit number.
  * The resource type for Verato API services is of the format: `/link-ws/svc/<resourceType>`. For this guide, we will be using `nativeIdQuery` as an example.
7. Select the **Auth** tab.
  * In the **Type** drop menu, select **Basic Auth** (Verato currently supports only BASIC Authentication mechanism).
  * Enter the username and password emailed to you by Verato.
8. Select **Settings**, and then select the settings icon.
9. Select **Certificates**, and then select **Add Certificate**.
10. Enter the following information, and then select **Add**.
  * **Host** - Use the hostname shared in the email sent to you by Verato.
  * **CRT File** - The `.cer` format of your certificate
  * **KEY File** - The `.pem` format of your certificate
  * **PFX File** - The `.p12` format of your certificate
  * **Passphrase** - Use your certificate password.
11. Select **Body**.
  * In the drop menu, select **Raw**.
  * In the Text drop menu, select **JSON**.
12. Copy paste an API request you would like to send, and then select **Send**.


If your connection was correctly configured, next to **Status** you should see a **200** status code in the response body.

> **Note:** If you do not see a **200** status code, verify all of the configuration information (passwords, URLs, certificates, etc.) for each step was configured properly. If you are still unable to receive a **200** status code, please submit a ticket to Verato Support.