Is a reverse proxy classified as anonymizing?
Not automatically. Spur distinguishes anonymizing proxies and tunnels from non-anonymizing ones. When Spur detects a tunnel or proxy, the anonymous flag indicates which: false for corporate or ZTNA infrastructure attributed as a tunnel but not anonymizing, and true for an anonymizing proxy service. Methodology can vary slightly by product — contact support if you need product-specific detail.
Similar questions
Why is a Cloudflare IP address classified as Anonymizing?
Some IPs belonging to a CDN like Cloudflare are classified as Anonymizing because they're used as the TLS entry point for an anonymizing tunnel service. The connecting client's TLS handshake names a legitimate-looking hostname, and the CDN routes the traffic to unrelated tunnel infrastructure behind it — the named domain and the CDN provider itself aren't involved in or aware of the proxying. In Spur's data this is reflected in the `tunnels` field, which distinguishes an IP's role as a tunnel entrance from its role as an exit. If your use case depends specifically on identifying egress points, you can filter out entrance-only IPs, since these are rarely also used as an exit for other services.
How does Spur classify infrastructure that serves more than one purpose, such as a legitimate corporate network also exposed through a public VPN service?
Spur classifies based on the most security-relevant observable behavior, not the primary or most benign use case. If otherwise-legitimate infrastructure is being publicly exposed through anonymizing or proxy services, it's labeled according to that exposure, since that's the behavior most relevant to a security decision.
How does Spur detect VPNs, residential proxies, and ISP proxies?
Spur uses a combination of network intelligence, infrastructure analysis, behavioral signals, routing characteristics, historical observations, and proprietary research to identify and classify IP addresses. Multiple signals are evaluated together to determine the likelihood that an IP belongs to a VPN, residential proxy network, ISP proxy service, hosting provider, or other category.
What should I do when I detect a VPN or proxy?
Detection alone should not automatically trigger a block. VPNs and proxies are used by both legitimate users and attackers. Most organizations incorporate VPN and proxy signals into broader risk-scoring or adaptive decisioning workflows that consider account history, geography, transaction context, and behavioral indicators.
Why might a residential IP be classified as a proxy?
Some residential IPs participate in proxy-sharing networks, malware-based proxy networks, commercial residential proxy services, or other infrastructure that causes them to exhibit proxy-like behavior. Spur evaluates multiple indicators before making classifications.
Related guides & explainers
Anonymizing vs. Non-Anonymizing Tunnels: What the "anonymous" Flag Means
Not every tunnel Spur detects is built to anonymize. The tunnels object's anonymous flag distinguishes corporate/ZTNA infrastructure from services designed to obscure a user's origin.
What "Client Proxies" Means in Spur Data
"Client Proxies" in Spur data describes proxy-network activity Spur observed coming from an IP — it does not mean the IP is owned or operated by the listed provider.
Why Residential Proxy Classifications Can Appear on Legitimate Infrastructure
Residential proxy networks recruit real consumer devices to relay traffic, so a legitimate ISP's own IP ranges can show a residential-proxy classification without the ISP's knowledge or involvement.
How Spur IP Classifications Work: Observed Behavior, Not IP Ownership
Spur classifications describe what was observed happening on an IP during a given window, not who owns the IP or ASN — a key distinction when investigating a classification that looks wrong.