Decoding Junos' SSL Proxy Functionality

The Juniper Networks Certified Specialist Enterprise Routing and Switching (JNCIS-ENT) certification is a highly sought-after credential in the IT networking industry. One of the key topics covered in the JNCIS-ENT certification is the SSL Proxy functionality in Junos. This blog post aims to provide a comprehensive understanding of this feature.

What is SSL Proxy?

SSL Proxy is a security feature in Junos that allows the device to decrypt and inspect SSL/TLS encrypted traffic. This is crucial in identifying and blocking potential threats hidden in encrypted traffic. SSL Proxy is typically used in conjunction with other security features such as IDP (Intrusion Detection and Prevention) and UTM (Unified Threat Management).

How does SSL Proxy work?

SSL Proxy works by acting as a 'man-in-the-middle' between the client and the server. When a client initiates an SSL/TLS session, the Junos device intercepts the request and establishes an SSL/TLS session with the server on behalf of the client. The Junos device then establishes a separate SSL/TLS session with the client. This allows the Junos device to decrypt and inspect the traffic before re-encrypting it and forwarding it to the intended recipient.

Configuring SSL Proxy

To configure SSL Proxy on a Junos device, you need to perform the following steps:

  1. Create an SSL Proxy profile

    The SSL Proxy profile contains the settings for the SSL Proxy feature. To create an SSL Proxy profile, use the following command:

    set services ssl proxy profile SSL-PROXY-PROFILE root-ca CA-CERTIFICATE

    Replace CA-CERTIFICATE with the name of the root CA certificate that the Junos device will use to sign the server certificates it generates.

  2. Apply the SSL Proxy profile to a security policy

    Once the SSL Proxy profile is created, you need to apply it to a security policy. The security policy determines the traffic that the SSL Proxy feature will inspect. To apply the SSL Proxy profile to a security policy, use the following command:

    set security policies from-zone FROM-ZONE to-zone TO-ZONE policy POLICY-NAME then permit application-services ssl-proxy profile SSL-PROXY-PROFILE

    Replace FROM-ZONE, TO-ZONE, POLICY-NAME, and SSL-PROXY-PROFILE with the appropriate values.


The SSL Proxy feature in Junos is a powerful tool for enhancing network security. By decrypting and inspecting SSL/TLS encrypted traffic, it allows the Junos device to identify and block potential threats that would otherwise go unnoticed. However, it's important to note that the use of SSL Proxy should be carefully considered due to the privacy implications of decrypting encrypted traffic.

Remember, the key to mastering any topic for the JNCIS-ENT certification is practice. So, make sure to get hands-on experience with configuring and troubleshooting the SSL Proxy feature in Junos. Good luck with your studies!

© Ben Jacobson.RSS