Which solution should a network administrator deploy to protect a webserver from SQL injection attacks?

An IDS (Intrusion Detection System) can identify and alert on SQL injection attempts but does not actively prevent the attack from reaching the web server; it lacks enforcement capabilities.

A Secure Web Appliance (SWA), particularly when acting as or integrating with a Web Application Firewall (WAF), is specifically designed to inspect HTTP/HTTPS traffic. It can detect and block malicious input patterns, such as those used in SQL injection attacks, before they reach the web server, providing dedicated application-layer protection.

Cisco Identity Services Engine (ISE) is primarily used for network access control, identity management, and policy enforcement based on user/device identity, not for protecting web applications from SQL injection attacks.

An IPS (Intrusion Prevention System) can block some known SQL injection signatures, but a dedicated WAF (often a feature of an SWA) offers more specialized, granular, and context-aware protection for web application vulnerabilities.