This guide will show you how to generate a CSR code and install an SSL Certificate on Zyxel ZyWall USG. It will also tell you a few interesting facts about Zyxel and reveal the best place where you can buy affordable SSL certificates.

If you’ve already generated a CSR code and applied for your certificate, skip this step and start following the installation instructions. Use the links below to navigate between different sections:

Generate CSR on Zyxel Zywall USG
Install an SSL certificate on Zyxel Zywall USG
Zyxel Zywall history
Where to buy the best SSL certificate for Zyxel Zywall USG?

Generate CSR on Zyxel Zywall USG

CSR stands for Certificate Signing Request, a block of encoded text with your contact data. To obtain a third-party SSL certificate, you need to generate the CSR and submit it to the Certificate Authority for validation. Here’s how to do it:

  1. Log into your Zywall web configurator.
  2. Go to Object > Certificate > My Orders
  3. Under My certificates, click the Add button, and enter your contact details:
  •  Name: This is a personal identifier. The name will appear under the My Certificates section. Name it in a way that will help you remember the certificate.
  • Common Name: Depending on the type of your connection, select either Host Domain Name or Host IP address.
  • Organizational Unit: This field is optional. You can leave it blank or enter the name of your unit. For instance, IT.
  • Organization: enter the full, legal name of your company. For Example, Your company LLC.
  • Country: this is another optional field. You can enter the two-letter country code for your country (i.e. US).
  • Key type: RSA
  • Key length: Select a minimum of 2048 bits
  • Enrollment options: Select”Create a certification request and save it locally for later manual enrollment“.
  1. You can now go to the My certificate details screen and retrieve the CSR. Copy and paste its contents in the relevant field when ordering your SSL certificate.

Install the SSL certificate on Zyxel Zywall USG

After your CA signs and sends your SSL certificate to your inbox, download it and extract its contents on your local machine.

If your certificate is in .cer or .p7b format do the following:

  1. Go to Object > Certificate > My Certificates
  2. In the web configurator, click Import
  3. Click browse and find your certificate file.
  4. Leave the password field blank, then click OK.
  5. Your certificate should now be installed.

If your certificate is in .crt format, you need to combine the files you’ve received into .pem format. Use a text editor such as Notepad and copy-paste the entire content of each certificate file into one single text. Follow the exact order shown below:

  1. The Primary Certificate – your_domain_name.crt
  2. The First Intermediate Certificate – yourCAname.crt
  3. The Second Intermediate Certificate (if a 2nd intermediate cert is supplied) –yourCA2name.crt
  4. The Root Certificate – TrustedRoot.crt

Note: the file names are just for example purposes.

The end result should look like this:


(Your Primary SSL certificate)



(Your First Intermediate certificate)



(Your Second Intermediate certificate (if applicable))



(Your Root certificate:)


Save the newly-combined .pem file. You can now install it on Zywall:

  1. Navigate to Object > Certificates > My certificates
  2. In the Web Configurator, click Import
  3. Select Browse and find your certificate file.
  4. Leave the password blank and click OK.
  5. That’s it! You’ve completed the installation successfully.

After you install an SSL Certificate on Zywall USG, you can check your configuration for potential errors or vulnerabilities. To do this efficiently, use one of these high-end SSL tools. Pick any tool from the linked article, and get instant scans and reports on your SSL Certificate.

Zyxel Zywall history

Zyxel (pronounced “zai-cell”) Communications Corp is a manufacturer of network devices. Headquartered in Taiwan, the company was founded in 1989 by Dr. Shun-I Chu. In 1992, Zyxel launched the world’s first integrated voice/fax modem. The company has pioneered many networking hardware devices including the world’s first ADSL2+ gateway and first palm-sized portable personal firewall.

The Zyxel Zywall USG is a fully-fledged security gateway that offers progressive security solutions. Thanks to its highly flexible configuration, it gives administrators the power to set up networks efficiently including the implementation of extensive security policies.

Where to buy the best SSL certificate for Zywall USG?

If you’re looking for a pleasant shopping experience, then SSL Dragon is a great option. Our intuitive and user-friendly website will smoothly walk you through the entire range of SSL Certificates. All our products are signed by trusted Certificate Authorities and are compatible with Zywall USG. We offer the following SSL validation types:

Enjoy the lowest prices on the market, and stellar customer support for any certificate you choose.

If you find any inaccuracies, or you have details to add to these SSL installation instructions, please feel free to send us your feedback at [email protected] Your input would be greatly appreciated! Thank you.