Which port is configured in a browser to use the Cisco WSA web proxy with default settings?

The Cisco Web Security Appliance (WSA) uses port 3128 as the default TCP port for the explicit forward web proxy service. When end-user browsers are configured to send web traffic to the WSA, they must be pointed to the IP address or hostname of the WSA and configured to use port 3128. This port is the standard listening port on the WSA's P1 (Proxy 1) interface for intercepting and inspecting HTTP and HTTPS requests from clients. While administrators can configure other ports, 3128 is the default setting.

B. 8443: This is the default port for accessing the WSA's graphical user interface (GUI) for management over a secure HTTPS connection.
C. 8021: This port is not used by default for any primary service on the Cisco WSA.

1. Cisco. (2021). AsyncOS 14.0 for Cisco Web Security Appliances - User Guide. "Configuring Web Proxy Listeners" section, Page 10-1. The guide states, "By default, the P1 interface on the appliance is enabled and the web proxy listens for proxy requests on port 3128 on all IP addresses associated with this interface."

2. Cisco. (2017). Cisco Web Security Appliance Best Practices Guide. "Deployment" section, "Explicit Forward Deployment," Page 10. This document notes, "The default proxy port is 3128. If you change the port, you must update the browser settings on the client machines."

3. Cisco. (2021). AsyncOS 14.0 for Cisco Web Security Appliances - CLI Reference Guide. "proxyconfig" command details, Page 20-208. The documentation for the proxyconfig > setup command shows that the default port presented for the proxy is 3128.